A supervisor records the repair cost for 22 randomly selected VCRs. A sample mean of $75.50 and standard deviation of $18.07 are subsequently computed. Determine the 99% confidence interval for the mean repair cost for the VCRs. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Answers

Answer 1

Answer:

The t value for 99% CI for 21 df is 2.831.

The critical value that should be used in constructing the confidence interval is (64.593, 86.407).

Step-by-step explanation:

Now the sample size is less than 30 and also population standard deviation is not known.

Then we will use t distribution to find CI

t value for 99% CI for 21 df is TINV(0.01,21)=2.831

The margin of error is [tex]E=t\times\frac{s}{\sqrt{n}}\\\\=2.831\times\frac{18.07}{\sqrt{22}}\\\\=10.907[/tex]

Hence CI is[tex]CI=\overline{x} \pm E\\\\ =75.50 \pm 10.907\\\\=(64.593,86.407 )[/tex]


Related Questions

Draw a graph of direct proportion, expressed by the formula: y=3x

Answers

Answer.

ANSWER

.......

if x¹=xcosA+ysinA and y¹=xsinA-ycosA, show that (x¹)²+(y¹)²=x²+y²​

Answers

Expanding each square on the left side, you have

(x cos(A) + y sin(A))² = x² cos²(A) + 2xy cos(A) sin(A) + y² sin²(A)

(x sin(A) - y cos(A))² = x² sin²(A) - 2xy sin(A) cos(A) + y² cos²(A)

so that adding them together eliminates the identical middle terms and reduces to the sum to

x² cos²(A) + y² sin²(A) + x² sin²(A) + y² cos²(A)

Collecting terms to factorize gives us

(y² + x²) sin²(A) + (x² + y²) cos²(A)

(x² + y²) (sin²(A) + cos²(A))

and sin²(A) + cos²(A) = 1 for any A, so we end up with

x² + y²

as required.

A noted psychic was tested for extrasensory perception. The psychic was presented with 200 cards face down and asked to determine if each card were one of five symbols: a star, a cross, a circle, a square, or three wavy lines. The psychic was correct in 50 cases. Let p represent the probability that the psychic correctly identifies the symbol on the card in a random trial. Assume the 200 trials can be treated as a simple random sample from the population of all guesses the psychic would make in his lifetime. How large a sample n would you need to estimate p with a margin of error of 0.01 with 95% confidence? Use the hypothesized value p = 0.20 as the value for p*.

Answers

Answer:

r3jehejn wbbwbwbbwmwkwkwjwjwhhejehehehhe

Please help! There is 2 questions in this pic! Thank you so much to whoever helps me

Answers

Answer:

[tex]{ \sf{thats \: it}}[/tex]

absolute value means they answer should be positive
ans |-13-17|=30
|-30|=30

2.5 cm in the ratio of 1:500000​

Answers

Answer:

1250000cm

Step-by-step explanation:

1:500000

1x2.5 : 500000x2.5

2.5:1250000

Fo quality control purposes, we collect a sample of 300 items and find 36 defective items in it. Construct a 90% confidence interval [a, b] for the proportion of defective items in the whole shipment.

Answers

Answer:

(0.089 ; 0.151)

Step-by-step explanation:

Given :

Sample size, n = 300

Number of defective items, x = 36

The confidence interval required here is that for a one sample proportion :

The confidence interval is defined thus :

Phat ± Zcritical * √[Phat(1 - phat) / n]

Zcritical at 90% = 1.645

Phat = x / n = 36 / 300 = 0.12

Hence,

C.I = 0.12 ± 1.645 * √[0.12(1 - 0.12) / 300]

C.I = 0.12 ± (1.645 * 0.0187616)

C.I = 0.12 ± 0.0308629

C.I = (0.089 ; 0.151)

Put the following equation of a line into slope-intercept form, simplifying all fractions 2x-2y=14

Answers

Answer:

y = x - 7

Step-by-step explanation:

Answer: y = x - 7

Slope intercept form: y = mx + b

[tex]2x-2y=14\\\\-2y=-2x+14\\\\y=\frac{-2x+14}{-2} =\frac{-2(x-7)}{-2} =x-7[/tex]

4.Siti and Janice spent 3h 25min altogether in Shopping malls A and B. If they spent 1h 45min in Shopping mall A, how long did they spend in Shopping mall B?

Answers

Answer:

1 hour and 40 minutes

Step-by-step explanation:

→ Convert 3 hr and 25 minutes to minutes

( 3 × 60 ) + 25 = 205 minutes

→ Convert 1 hr and 45 minutes to minutes

( 1 × 60 ) + 45 = 105 minutes

→ Minus the answers from each other

205 - 105 = 100 minutes

→ Convert 100 minutes to hours and minutes

1 hour and 40 minutes

Classify the following data. Indicate whether the data is qualitative or quantitative, indicate whether the data is discrete, continuous, or neither, and indicate the level of measurement for the data.
A supervisor must give a summary evaluation rating from among the choices given below:
1) Poor   
2) Fair   
3) Good   
4) Very good   
5) Excellent
a. Are these data qualitative or quantitative?
b. Are these data discrete or continuous?
c. What is the highest level of measurement the data possesses?

Answers

Answer:

Qualitative data

Neither discrete or continous

Ordinal

Step-by-step explanation:

Qualitative data simply refers to Non-numeric measure, they make use of data labels which are expressed in words rather than figures or numbers.

For a data to be either discrete or continous, then it has to be numeric, since the data is qualitative and non- numeric, then it is neither continous or discrete.

This is an ordinal scale representation of data as data are ordered or ranked in terms of performance, however, there is no measure of difference between each rank or order. The highest level of performance in the scale is Excellent.

Find the area enclosed in the graph of
x² + y² 16x + 32y.

Answers

Answer:

3

256

sq.units

Step-by-step explanation:

Both parabolas cut each other at (0,0) and (16,16)

Area enclosed by these parabolas

=∫

0

16

4

x

dx−∫

0

16

16

x

2

dx

=[

3

2×4×x

3/2

]

0

16

−[

16×3

x

3

]

0

16

=

3

2×4

4

3

4

4

=

3

256

sq. units

Determine whether the following polygons are similar. If yes, type 'yes' in the Similar box and type in the similarity statement and scale factor. If no, type 'None' in the blanks. For the scale factor, please enter a fraction. Use the forward dash (i.e. /) to create a fraction (e.g. 1/2 is the same as 12
1
2
).

Answers

Given:

The figures of two polygons.

To find:

Whether the polygons are similar and then find the scale factor (if similar).

Solution:

From the given figures it is clear that both polygons are rectangles and their all interior angles are right angles.

The ratio of their longer sides:

[tex]\dfrac{32}{26}=\dfrac{16}{13}[/tex]

The ratio of their shorter sides:

[tex]\dfrac{18}{12}=\dfrac{3}{2}[/tex]

Since the ratio of their corresponding sides are not equal, therefore the two polygons are not similar.

Therefore the required solutions are:

Similar : No

Similarity statement : None

Scale factor : None

write your answer in simplest radical form​

Answers

Answer:

q = [tex]\sqrt{2}[/tex]

Step-by-step explanation:

Using the sine ratio in the right triangle and the exact value

sin30° = [tex]\frac{1}{2}[/tex] , then

sin30° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{q}{2\sqrt{2} }[/tex] = [tex]\frac{1}{2}[/tex] ( cross- multiply )

2q = 2[tex]\sqrt{2}[/tex] ( divide both sides by 2 )

q = [tex]\sqrt{2}[/tex]

If p is a given sample proposition n is the sample size, and a is the number of standard deviations at a confidence level, what is the standard error of the proportion?

Answers

Answer:

The standard error of a proportion p in a sample of size n is given by: [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Step-by-step explanation:

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]

In this question:

The standard error of a proportion p in a sample of size n is given by: [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Which
sequences are geometric? Check all that apply. 5, 10, 20, 50

Answers

Answer:

not geometric

Step-by-step explanation:

The ratios of the numbers in the sequence 5, 10, 20, 50 are 2, 2, 2.5. That is, the ratios are not constant. Hence the sequence is not geometric.

Answer:

76K would find this fake but.....

Step-by-step explanation:

Non geometrical

In an experiment, the initial temperature of a solution is -5 °C. The solution is heated up at 3 °C per minute for 19 minutes and then it is cooled at 4 °C per minute for 6 minutes. Calculate the final temperature, in °C, of the solution.​

Answers

Answer:

28°C

Step-by-step explanation:

First you do 3*19=57°C

-5+57= 52°C

then you do 4*6=24 °C

as its being cooled you takeaway

52-24=28°C

Find two power series solutions of the given differential equation about the ordinary point x = 0. Compare the series solutions with the solutions of the differential equation obtained using the method of Section 4.3. Try to explain any differences between the two forms of the solution. y'' − y' = 0 y1 = 1 − x2 2! + x4 4! − x6 6! + and y2 = x − x3 3! + x5 5! − x7 7! + y1 = x and y2 = 1 + x + x2 2! + x3 3! + y1 = 1 + x2 2! + x4 4! + x6 6! + and y2 = x + x3 3! + x5 5! + x7 7! + y1 = 1 + x and y2 = x2 2! + x3 3! + x4 4! + x5 5! + y1 = 1 and y2 = x + x2 2! + x3 3! + x4 4! +

Answers

You're looking for a solution in the form

[tex]y(x) = \displaystyle \sum_{n=0}^\infty a_nx^n[/tex]

Differentiating, we get

[tex]y'(x) = \displaystyle \sum_{n=0}^\infty na_nx^{n-1} = \sum_{n=1}^\infty na_nx^{n-1} = \sum_{n=0}^\infty (n+1)a_{n+1}x^n[/tex]

[tex]y''(x) = \displaystyle \sum_{n=0}^\infty (n+1)na_{n+1}x^{n-1} = \sum_{n=1}^\infty (n+1)na_{n+1}x^{n-1} = \sum_{n=0}^\infty (n+2)(n+1)a_{n+2}x^n[/tex]

Substitute these for y' and y'' in the differential equation:

[tex]\displaystyle \sum_{n=0}^\infty (n+2)(n+1)a_{n+2}x^n - \sum_{n=0}^\infty (n+1)a_{n+1}x^n = 0[/tex]

[tex]\displaystyle \sum_{n=0}^\infty \bigg((n+2)(n+1)a_{n+2}-(n+1)a_{n+1}\bigg)x^n = 0[/tex]

Then the coefficients of y are given by the recurrence

[tex]\begin{cases}a_0=y(0)\\a_1=y'(0)\\a_{n+2}=\frac{a_{n+1}}{n+2}&\text{for }n\ge0\end{cases}[/tex]

or

[tex]a_n = \dfrac{a_{n-1}}n[/tex]

But we cannot assume that [tex]a_0[/tex] and [tex]a_1[/tex] depend on each other; we can only guarantee that the recurrence holds for n ≥ 1, so that

[tex]a_2=\dfrac{a_1}2 \\\\ a_3=\dfrac{a_2}3=\dfrac{a_1}{3\times2} \\\\ a_4=\dfrac{a_3}4=\dfrac{a_1}{4\times3\times2} \\\\ \vdots \\\\ a_n=\dfrac{a_1}{n!}[/tex]

So in the power series solution, we split off the constant term and we're left with

[tex]y(x) = a_0 + a_1 \displaystyle \sum_{n=1}^\infty \frac{x^n}{n!}[/tex]

so that the fundamental solutions are

[tex]y_1=1[/tex]

and

[tex]y_2=x+\dfrac{x^2}{2!}+\dfrac{x^3}{3!}+\dfrac{x^4}{4!}+\cdots[/tex]

I'm stuck. Can anyone help please?

Answers

log₉(x - 7) + log₉(x - 7) = 1

2 log₉(x - 7) = 1

log₉(x - 7) = 1/2

Take the base-9 antilogarithm of both sides; in other words, make both sides powers of 9:

[tex]9^{\log_9(x-7)} = 9^{1/2}[/tex]

[tex]9^{1/2}[/tex] can also be written as √9 = 3, and [tex]b^{\log_b(a)}=a[/tex], so the equation reduces to

x - 7 = 3

Solve for x :

x = 10

I need help ASAP thank you

Answers

Answer:

√9 × √6

√54

√27 × √2

Step-by-step explanation:

We can obtain the answer to the question given above as illustrated below:

3√6

Recall

a√b = √(a×a×b)

Thus,

3√6 = √(3×3×6)

3√6 = √(9 × 6)

Recall

√(a × b) = √a × √b

√(9 × 6) = √9 × √6

Therefore,

3√6 = √9 × √6

Recall

√9 × √6 = √(9 × 6)

√9 × √6 = √54

Thus,

3√6 = √54

Recall

√54 = √(27 × 2)

√54 = √27 × √2

Therefore,

3√6 = √27 × √2

Therefore,

3√6 = √9 × √6 = √54 = √27 × √2

What is the equation of a line that passes through the point (5,-3) and has a slope of -2

Answers

Answer:

y=-2x+7

Step-by-step explanation:

The Slope is obviously -2, and just add a random y and play around with it until it goes through the point (5,-3)

the two roots a minus the square root of b and a plus the square root of b are called

Answers

Answer:

The two roots a+√b and a-√b are called Conjugate radicals

Step-by-step explanation:

I'd really appreciate a brainleast:)

At a restaurant, two burgers and one fries cost 6. 50. What is the cost of six burgers and three fries

Answers

Answer:

19.5

Step-by-step explanation:

let burger be x and fries be y

2x+y = 6.5

6x+3y = 3(2x+y) =3(6.5) =19.5

The length of a rectangle is 7 inches
more inan its width. the area of
the rectangle is eqaul to 4 inches less
than 4 times the perimeter. Find the
length and width of the rectangle

Answers

Answer:

length = 20 inches

width = 13 inches

Step-by-step explanation:

l = length

w = width

area = l×w

perimeter = (2×l) + (2×w)

l = w + 7

l×w = 4×(2×l + 2×w) - 4

(w+7)×w = 4×(2×(w+7) + 2×w) - 4

w² + 7w = 4×(2w + 14 + 2w) - 4

w² + 7w = 8w + 56 + 8w - 4 = 16w + 52

w² - 9w - 52 = 0

the solution for a quadratic equation is

x = (-b ± sqrt(b² - 4ac))/(2a)

here we use now w instead of x.

and a=1

b=-9

c=-52

w = (9 ± sqrt(81 - -208))/2 = (9 ± sqrt(81+208))/2 =

= (9 ± sqrt(289))/2 = (9 ± 17)/2

w1 = (9+17)/2 = 26/2 = 13

w2 = (9-17)/2 = -8/2 = -4

and a negative length does not make any sense for a geometric shape.

so, only w1 = 13 applies.

l = w + 7 = 13 + 7 = 20

please help me with geometry

Answers

Answer:

A. If the side lengths are the same, then a triangle is not scalene.

Step-by-step explanation:

A triangle can be defined as a two-dimensional shape that comprises three (3) sides, three (3) vertices and three (3) angles.

Simply stated, any polygon with three (3) lengths of sides is a triangle.

In Geometry, a triangle is considered to be the most important shape.

Generally, there are three (3) main types of triangle based on the length of their sides and these include;

I. Equilateral triangle: it has all of its three (3) sides and interior angles equal.

II. Isosceles triangle: it has two (2) of its sides equal in length and two (2) equal angles.

III. Scalene triangle: it has all of its three (3) sides and interior angles different in length and size respectively.

What is a corresponding pair for f(-7)=5

Answers

Answer:

An ordered pair for a function f(x) looks like (x, f(x)). So the ordered pair here would be (5, f(5)) or (5, 7). Either one would work, as they are the same.

A box of 8 marbles has 4 red, 2 green, and 2 blue marbles. If you select one marble, what is the probability that it is a red or blue marble.

Answers

Answer:

3/4

Step-by-step explanation:

add the no. of red marbles and blue marbles

2+4 = 6

Probability so divide 6/8 simplified to 3/4

The population p(t) of a culture of the bacterium Pseudomonas aeruginosa is given by ,p(t)= -1683t^2+75,000t+ 10,000 where is the time in hours since the culture was started. Determine the time the population was at its maximum. Round to the nearest hour.

Answers

Answer:

22hrs

Step-by-step explanation:

hope it is well understood?

Find the area of the quadrilateral and round to the nearest tenth

Answers

Answer:

24

Step-by-step explanation:

(4+8)×4/2

= 12×4/2

= 24

Answered by GAUTHMATH

which lines are parallel?

Answers

Answer:

Lines 'p' and 'q' are parallel I believe!

Step-by-step explanation:

They are the only two lines relating to angles 8 and 11 of the three listed pairs.

Answer:

p and q are parallel

Step-by-step explanation:

A two-digit number is of the number
7
formed by reversing its digits. When the
number is increased by 2 times the sum of
its digits, it becomes 54. Find the number.

Answers

Answer:

C

Step-by-step explanation:


At a birthday party there were five more girls than boys. If the ratio of girls to boys was 4 to 3,
how many girls were at the party? (Make a chart to help you.)

Answers

Let number if boys be x

No of girls=x+5

ATQ

[tex]\\ \sf\longmapsto \dfrac{x+5}{x}=\dfrac{4}{3}[/tex]

[tex]\\ \sf\longmapsto 3(x+5)=4x[/tex]

[tex]\\ \sf\longmapsto 3x+15=4x[/tex]

[tex]\\ \sf\longmapsto 4x-3x=15[/tex]

[tex]\\ \sf\longmapsto x=15[/tex]

Number of girls

[tex]\\ \sf\longmapsto x+5=15+5=20[/tex]

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