Many freeways have service (or logo) signs that give information on attractions, camping, lodging, food, and gas services prior to off-ramps. These signs typically do not provide information on distances. An article reported that in one investigation, six sites along interstate highways where service signs are posted were selected. For each site, crash data was obtained for a three-year period before distance information was added to the service signs and for a one-year period afterward. The number of crashes per year before and after the sign changes were as follows.
Before 13 22 65 123 56 63
After 14 21 43 84 75 72
1. The article included the statement "A paired t-test was performed to determine whether there was any change in the mean number of crashes before and after the addition of distance information on the signs." Carry out such a test. (Note: The relevant normal probability plot shows a substantial linear pattern.)
a. State and test the appropriate hypotheses. (Use α = 0.05.)
b. Calculate the test statistic and P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.)
t = _____
p-value = _____
c. State the conclusion in the problem context.
A. Fail to reject H0. The data does not suggest a significant mean difference in the average number of accidents after information was added to road signs.
B. Reject H0. The data suggests a significant mean difference in the average number of accidents after information was added to road signs.
C. Fail to reject H0. The data suggests a significant mean difference in the average number of accidents after information was added to road signs.
D. Reject H0. The data does not suggest a significant mean difference in the average number of accidents after information was added to road signs.
2. If a seventh site were to be randomly selected among locations bearing service signs, between what values would you predict the difference in the number of crashes to lie? (Use a 95% prediction interval. Round your answers to two decimal places.)

[tex] \frac{5}{3} = \frac{12}{x} \\ = > \frac{5x}{3} = 12 \\ = > 5x = 12 \times 3 \\ = > 5x = 36 \\ = > x = \frac{36}{5} \\ = > x = 7.2[/tex]

This is the answer.

Answer:

plato screenshot!

Step-by-step explanation:

I don't personally know *how* to find the answers, but here's the screenshot of the suggested answer on Plato

Answer:

A B Slope of  C Slope of Line Through C

(−5,4) (−1,−1) −1.25 (1,2) 0.8

(−5,4) (−3, 5) 0.5 (−2, 1) −2

(−4, 1) (−3, 5) 4 (−2, −2) −0.25

(−5, −2) (−1, 1) 0.75 (−4, 3) −1.33

(−5, −2) (1, −1) 0.17 (−3, 1) −6

Step-by-step explanation:

that way you can copy and paste each one but Plato

Answer:

t = 22 s

Step-by-step explanation:

If n is the number of strobe pulses

The first strobe pulse occurs at t = 0

t = 2(n - 1)

t = 2(12 - 1)

t = 2(11)

t = 22 s

Answer:

4999500

Step-by-step explanation:

first 5 = 5000000

second 5 = 500

difference = 5000000-500

Answer:

y = csc(x) does not have any zero.

Step-by-step explanation:

If we have:

y = f(x)

a zero of that function would be a value x' such that:

y = f(x') = 0

Here we basically want to solve:

y = csc(x) = 0

First, remember that:

csc(x) = 1/sin(x)

now, the values of sin(x) range from -1 to 1.

So we want to solve:

1/sin(x) = 0

notice that a fraction:

a/b = 0

only if a = 0.

Then is easy to see that for our equation:

1/sin(x) = 0

The numerator is different than zero, then the equation never will be equal to zero.

Then:

y = csc(x) = 1/sin(x)

Does not have a zero.

Answer:

z(max) = 16

z(min) = -24

Step-by-step explanation:

2x - y = 12  multiply by 2

4x - 2y = 24  (1)

4x + 2y = 0  add equations

8x = 24

x = 3

4(3) + 2y = 0

y = -6

so (3, -6) is a common point on these two lines

z = 2(3) + 5(-6) = -24

4x - 2y = 24   (1)

x + 2y = 6   add equations

      5x = 30

        x = 6

6 + 2y = 6

         y = 0

so (6, 0) is a common point on these two lines

z = 2(6) + 5(0) = 12

4x + 2y = 0    multiply by -1

-4x - 2y = 0

  x + 2y = 6  add equations

       -3x = 6

         x = -2

-2 + 2y = 6

         y = 4

so (-2, 4) is a common point on these two lines

z = 2(-2) + 5(4) = 16

Answer:

Pencils = 325 ; Pens = 975 ; Markers = 650

Step-by-step explanation:

Let :

Number of Pencils = x

Number of pens = y

Number of markers = z

2 times as many markers as pencils

z = 2x

3 times as many pens as pencils

y = 3x

x + y + z = 1950

Write z and y in terms of x in the equation :

x + 3x + 2x = 1950

6x = 1950

Divide both sides by 6

6x / 6 = 1950 / 6

x = 325

Number of pencils = 325

Pens = 3 * 325 = 975

Markers = 2 * 325 = 650

Pencils = 325 ; Pens = 975 ; Markers = 650

Answer:

395.52

Step-by-step explanation:

247.2/2.5=98.88(1 bib)

98.88x4=395.52(4 bibs)

9514 1404 393

Answer:

  3.6481 years

Step-by-step explanation:

The doubling time is not a function of the amount invested. It can be found by considering the account balance multiplier:

  2 = e^(rt) = e^(0.19t)

Taking logs, we can solve for t:

  ln(2) = 0.19t

  t = ln(2)/0.19 ≈ 3.6481431

Rounded to 4 decimal places, the doubling time is 3.6481 years, for either balance.

Answer:

200 is equal to 20 tens I guess lol

Answer:

20 tens

Step-by-step explanation:

200÷10=20 groups of ten

Answer:

y = 3.6

x = 3.5

Step-by-step explanation:

The triangles are similar.

[tex]\frac{3}{2.4} = \frac{x}{2.8} = \frac{4.5}{y}[/tex]

Find y:

[tex]\frac{4.5}{y} = \frac{5}{4}[/tex]

[tex]4.5 * 4 = 5y => 18 = 5y => y = 3.6[/tex]

Find x:

[tex]\frac{x}{2.8} = \frac{5}{4}[/tex]

[tex]2.8 * 5 = 4x => 14 = 4x => x = 3.5[/tex]

Answer: [tex]10,000\ lb.ft[/tex]

Step-by-step explanation:

Given

Initial weight of the bucket is [tex]145\ lb[/tex]

It is lifted at constant rate and rate of sand escaping is [tex]0.5\ lb/ft[/tex]

At any height weight of the sand is [tex]w(h)=145-0.5h[/tex]

Work done is given by the product of applied force and displacement or the area under weight-displacement graph

from the figure area is given by

[tex]\Rightarrow W=\int_{0}^{80}\left ( 145-0.5h \right )dh\\\\\Rightarrow W=\left | 145h-\dfrac{0.5h^2}{2} \right |_0^{80}\\\\\Rightarrow W=\left [ 145\times 80-\dfrac{0.5(80))^2}{2} \right ]-0\\\\\Rightarrow W=11,600-1600\\\\\Rightarrow W=10,000\ lb.ft[/tex]

Answer:

[tex]\begin{array}{cc}{Status} & {Probability} & {1} & {0.0845} & {2} & {0.1127} & {3} & {0.1870} & {4} & {0.1927}& {5} & {0.4231} \ \end{array}[/tex]

Step-by-step explanation:

Given

The above table

Required

The discrete probability distribution

The probability of each is calculated as:

[tex]Pr = \frac{Frequency}{Total}[/tex]

Where:

[tex]Total = 2140+ 2853 + 4734 + 4880 + 10715[/tex]

[tex]Total = 25322[/tex]

So, we have:

[tex]P(1) = \frac{2140}{25322} = 0.0845[/tex]

[tex]P(2) = \frac{2853}{25322} = 0.1127[/tex]

[tex]P(3) = \frac{4734}{25322} = 0.1870[/tex]

[tex]P(4) = \frac{4880}{25322} = 0.1927[/tex]

[tex]P(5) = \frac{10715}{25322} = 0.4231[/tex]

So, the discrete probability distribution is:

[tex]\begin{array}{cc}{Status} & {Probability} & {1} & {0.0845} & {2} & {0.1127} & {3} & {0.1870} & {4} & {0.1927}& {5} & {0.4231} \ \end{array}[/tex]

Answer:

x=15, y=5

Step-by-step explanation:

x+y=20

x-y=10

Adding both equations;

(x+x) + (y-y) = 20+10

2x = 30

x = 30/2 = 15

Substitute x=15 into x+y=20

y= 20-x = 20-15= 5

Given:

The inequality is:

[tex]|2x-1|>3[/tex]

To find:

The solution set for the given inequality.

Solution:

We know that, if [tex]|x|>a[/tex], then [tex]x<-a[/tex] and [tex]x>a[/tex].

We have,

[tex]|2x-1|>3[/tex]

It can be written as:

[tex]2x-1<-3[/tex] or [tex]2x-1>3[/tex]

Case I:

[tex]2x-1<-3[/tex]

[tex]2x<-3+1[/tex]

[tex]2x<-2[/tex]

[tex]x<\dfrac{-2}{2}[/tex]

[tex]x<-1[/tex]

Case II:

[tex]2x-1>3[/tex]

[tex]2x>3+1[/tex]

[tex]2x>4[/tex]

[tex]x>\dfrac{4}{2}[/tex]

[tex]x>2[/tex]

The required solution for the given inequality is [tex]x<-1[/tex] or [tex]x>2[/tex]. The solution set in the interval notation is [tex](-\infty,-1)\cup (2,\infty)[/tex].

Therefore, the required solution set is [tex](-\infty,-1)\cup (2,\infty)[/tex].

Answer:

Yes the sales manager claims can be refuted based on the calculated percentages

Step-by-step explanation:

From the table attached below

Total number of customers = 200

Calculated percentages

customers that prefer whole life insurance = 90 = 90/200 = 45%

customers that prefer universal life insurance = 15 = 15/200 = 7.5%

customers that prefer Annuities = 95 = 95/200 = 47.5

Expected percentages:

whole life = 20%

Universal life = 10%

Life Annuities = 70%

Answer:

[tex] - 3(x + 4) {}^{2} - 4[/tex]

Step-by-step explanation:

Vertex form is

[tex]a(x - h) {}^{2} + k = f(x)[/tex]

We know that h and k are both -4. Let x be -2 and y be -16.

[tex]a( - 2 + 4) {}^{2} - 4 = - 16[/tex]

[tex]a(2) {}^{2} - 4 = - 16[/tex]

[tex]4a - 4 = - 16[/tex]

[tex]4a = - 12[/tex]

[tex]a = - 3[/tex]

So the equation in vertex form is

[tex] - 3(x + 4) {}^{2} - 4[/tex]

the answer is 2B divided by A minus 3

Answer:

a) P(79 <= P <= 81) = 0.9968

b) P( X >  81 ) = 0.0002

Step-by-step explanation:

mean value = 75 GPa

standard deviation = 1.7 GPa

a) Determine P(79 <= P <= 81)

given that : n = 25

attached below is the detailed solution

P(79 <= P <= 81) = 0.9968

b) Determine how likely the sample mean diameter will exceed 81

given that n = 36

mean diameter = 81

P( X >  81 ) = 0.0002

Answer:

Yes one should consider to buy the policy as important to have insured plan that help at the time of need.

Step-by-step explanation:

Answer:

\I got not answer cause im da BUDDHA

But gimme brainliest squekky plssss

Answer:

The idea is to transform the expression by multiplying [tex](\sqrt{x + 1} - \sqrt{x})[/tex] with its conjugate, [tex](\sqrt{x + 1} + \sqrt{x})[/tex].

Step-by-step explanation:

For any real number [tex]a[/tex] and [tex]b[/tex], [tex](a + b)\, (a - b) = a^{2} - b^{2}[/tex].

The factor [tex](\sqrt{x + 1} - \sqrt{x})[/tex] is irrational. However, when multiplied with its square root conjugate [tex](\sqrt{x + 1} + \sqrt{x})[/tex], the product would become rational:

[tex]\begin{aligned} & (\sqrt{x + 1} - \sqrt{x}) \, (\sqrt{x + 1} + \sqrt{x}) \\ &= (\sqrt{x + 1})^{2} -(\sqrt{x})^{2} \\ &= (x + 1) - (x) = 1\end{aligned}[/tex].

The idea is to multiply [tex]\sqrt{x}\, (\sqrt{x + 1} - \sqrt{x})[/tex] by [tex]\displaystyle \frac{\sqrt{x + 1} + \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}[/tex] so as to make it easier to take the limit.

Since [tex]\displaystyle \frac{\sqrt{x + 1} + \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} = 1[/tex], multiplying the expression by this fraction would not change the value of the original expression.

[tex]\begin{aligned} & \lim\limits_{x \to \infty} \sqrt{x} \, (\sqrt{x + 1} - \sqrt{x}) \\ &= \lim\limits_{x \to \infty} \left[\sqrt{x} \, (\sqrt{x + 1} - \sqrt{x})\cdot \frac{\sqrt{x + 1} + \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}\right] \\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}\, ((x + 1) - x)}{\sqrt{x + 1} + \sqrt{x}} \\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}}{\sqrt{x + 1}+ \sqrt{x}}\end{aligned}[/tex].

The order of [tex]x[/tex] in both the numerator and the denominator are now both [tex](1/2)[/tex]. Hence, dividing both the numerator and the denominator by [tex]x^{(1/2)}[/tex] (same as [tex]\sqrt{x}[/tex]) would ensure that all but the constant terms would approach [tex]0[/tex] under this limit:

[tex]\begin{aligned} & \lim\limits_{x \to \infty} \sqrt{x} \, (\sqrt{x + 1} - \sqrt{x}) \\ &= \cdots\\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}}{\sqrt{x + 1}+ \sqrt{x}} \\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x} / \sqrt{x}}{(\sqrt{x + 1} / \sqrt{x}) + (\sqrt{x} / \sqrt{x})} \\ &= \lim\limits_{x \to \infty}\frac{1}{\sqrt{(x / x) + (1 / x)} + 1} \\ &= \lim\limits_{x \to \infty} \frac{1}{\sqrt{1 + (1/x)} + 1}\end{aligned}[/tex].

By continuity:

[tex]\begin{aligned} & \lim\limits_{x \to \infty} \sqrt{x} \, (\sqrt{x + 1} - \sqrt{x}) \\ &= \cdots\\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}}{\sqrt{x + 1}+ \sqrt{x}} \\ &= \cdots \\ &= \lim\limits_{x \to \infty} \frac{1}{\sqrt{1 + (1/x)} + 1} \\ &= \frac{1}{\sqrt{1 + \lim\limits_{x \to \infty}(1/x)} + 1} \\ &= \frac{1}{1 + 1} \\ &= \frac{1}{2}\end{aligned}[/tex].

Answer:

Hello,

Step-by-step explanation:

[tex]\displaystyle \lim_{x \to \infty} \sqrt{x}*(\sqrt{x+1}-\sqrt{x} ) \\\\\\= \lim_{x \to \infty}\dfrac{ \sqrt{x}*(\sqrt{x+1}-\sqrt{x} )*(\sqrt{x+1}+\sqrt{x} )}{\sqrt{x+1} +\sqrt{x} } \\\\= \lim_{x \to \infty} \dfrac{\sqrt{x} *1}{\sqrt{x+1} +\sqrt{x} } \\\\\\= \lim_{x \to \infty} \dfrac{1} {\sqrt {\dfrac {x+1} {x} }+\sqrt{\dfrac{x}{x} } } \\\\\\=\dfrac{1} {\sqrt {1}+\sqrt{1} } \\\\\\=\dfrac{1} {2} \\[/tex]

Answer:

The p-value of the test is 0.4414, higher than the standard significance level of 0.05, which means that there is not a a significant difference in the proportion of apartment dwellers and home owners who own artificial Christmas trees.

Step-by-step explanation:

Before testing the hypothesis, we need to understand the central limit theorem and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

Apartment:

38 out of 78, so:

[tex]p_A = \frac{38}{78} = 0.4872[/tex]

[tex]s_A = \sqrt{\frac{0.4872*0.5128}{78}} = 0.0566[/tex]

Home:

46 out of 84, so:

[tex]p_H = \frac{46}{84} = 0.5476[/tex]

[tex]s_H = \sqrt{\frac{0.5476*0.4524}{84}} = 0.0543[/tex]

Test if the there a significant difference in the proportion of apartment dwellers and home owners who own artificial Christmas trees:

At the null hypothesis, we test if there is no difference, that is, the subtraction of the proportions is equal to 0, so:

[tex]H_0: p_A - p_H = 0[/tex]

At the alternative hypothesis, we test if there is a difference, that is, the subtraction of the proportions is different of 0, so:

[tex]H_1: p_A - p_H \neq 0[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.

0 is tested at the null hypothesis:

This means that [tex]\mu = 0[/tex]

From the samples:

[tex]X = p_A - p_H = 0.4872 - 0.5476 = -0.0604[/tex]

[tex]s = \sqrt{s_A^2 + s_H^2} = \sqrt{0.0566^2 + 0.0543^2} = 0.0784[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{-0.0604 - 0}{0.0784}[/tex]

[tex]z = -0.77[/tex]

P-value of the test and decision:

The p-value of the test is the probability of the difference being of at least 0.0604, to either side, plus or minus, which is P(|z| > 0.77), given by 2 multiplied by the p-value of z = -0.77.

Looking at the z-table, z = -0.77 has a p-value of 0.2207.

2*0.2207 = 0.4414

The p-value of the test is 0.4414, higher than the standard significance level of 0.05, which means that there is not a a significant difference in the proportion of apartment dwellers and home owners who own artificial Christmas trees.

Answer: 1.28571428571. This number is infinite.

Step-by-step explanation:

Answer:

1.29 rounded

Step-by-step explanation:

Answer:

The original height of the plant was 2 mm

Step-by-step explanation:

Given

[tex]y = 2 + 4x[/tex]

Required

Interpret the y-intercept

The y-intercept is when [tex]x = 0[/tex]

So, we have:

[tex]y = 2 + 4 *0[/tex]

[tex]y = 2 + 0[/tex]

[tex]y = 2[/tex]

This implies that the original or initial height was 2 mm

[tex] - | 4 | < x < - |1| [/tex]

dunno if that's the desired form tough, but it states the same definition

The given inequality rewritten using absolute value sign​ as |-4|<x<|-1|.

Inequalities are the mathematical expressions in which both sides are not equal. In inequality, unlike in equations, we compare two values. The equal sign in between is replaced by less than (or less than or equal to), greater than (or greater than or equal to), or not equal to sign.

The given inequality is -4<x<-1.

An absolute value inequality is an expression with absolute functions as well as inequality signs.

Here, using absolute value sign​ we get

|-4|<x<|-1|

Therefore, the given inequality rewritten using absolute value sign​ as |-4|<x<|-1|.

To learn more about the inequalities visit:

https://brainly.com/question/20383699.

#SPJ2

Answer:

B

Step-by-step explanation:

-2/3x<31/3

x>-31/2

x>-15 1/2

Answer:

x > - 15 1/2

Step-by-step explanation:

-2/3 x -10 < 1/3

Multiply each side by 3

3(-2/3 x -10 < 1/3)

-2x -30 < 1

Add 30 to each side

-2x-30+30 <1+30

-2x < 31

Divide by -2 remembering to flip the inequality

-2x/-2 > 31/-2

x > -31/2

x > - 15 1/2

Complete question is;

The cost of producing x units of a particular commodity is C(x) = ⅔x² + 6x + 45 shillings and the production level t hours into a particular production run is x(t) = 0.3t² + 0.04t. At what rate is cost changing with respect to time after 5 hours?

Answer:

dC/dt = 49.45

Step-by-step explanation:

Since C(x) = ⅔x² + 6x + 45

And x(t) = 0.3t² + 0.04t

This means that;

C(x) = C(x(t))

The rate at what cost is changing with respect to time is given as;

dC/dt

Thus, from chain rule;

dC/dt = (dC/dx) × (dx/dt)

dC/dx = (4/3)x + 6

dx/dt = 0.6t + 0.04

Now, when t = 5, then;

x(5) = 0.3(5)² + 0.04(5)

x = 7.7

Thus;

dC/dx = (4/3)x + 6 = (4/3)(7.7) + 6 = 16.267

At 5 hours,

dx/dt = 0.6(5) + 0.04 = 3.04

Thus;

dC/dt = 16.267 × 3.04

dC/dt = 49.45