Please help. Also my answers are wrong.

Answer:

1a)Confidence Interval: (77.936,82.064)

b)Confidence Interval: (79.020, 80.980)

c)Confidence Interval: (79.510, 80.490)

d) As the sample size increases, the confidence interval for the lower class (bound) increases while that of the upper class(bound) decreases.

2a)Confidence Interval: (491.609

, 502.797)

b)Confidence Interval: (483.218, 516.782)

c)Confidence Interval: (466.436,533.564)

d)As the standard deviation increases, the confidence interval for the lower class (bound) decreases while that of the upper class(bound) increases.

Step-by-step explanation:

1 a) A random sample of 25 was drawn from a normal distribution with a standard deviation of 5. The sample mean is 80.

The formula for confidence Interval is:

C.I = Mean ± z score × Standard deviation/√n

Note to apply the formula above n greater than or equal to 30

a) Determine the 95% confidence interval estimate of the population mean.

For a, the confidence interval formula above cannot be applied because n is less than 30, so we use the t score confidence interval value

C.I = Mean ± t score × Standard deviation/√n

Mean = 80

Standard deviation = 5

n = 25

Degree of freedom = 25 - 1 = 24

Hence, 95% confidence interval degree of freedom t score = 2.064

Hence, Confidence Interval =

80 ± 2.064 × 5/√25

80 ± 2.064 × 1

80 ± 2.064

Confidence Interval =

80 - 2.064

= 77.936

80 + 2.064

= 82.064

Confidence Interval: (77.936, 82.064)

b) Repeat part (a) with a sample size of 100.

C.I = Mean ± z score × Standard deviation/√n

Mean = 80

Standard deviation = 5

n = 100

z score for 95% confidence interval = 1.96

C.I = 80 ± 1.96 × 5/√100

C.I = 80 ± 1.96 × 5/10

C.I = 80 ± 1.96 × 0.5

C.I = 80 ± 0.980

Confidence Interval =

80 - 0.980

= 79.020

80 + 0.980

= 80.980

Confidence Interval: (79.020, 80.980)

c) Repeat part (a) with a sample size of 400.

C.I = Mean ± z score × Standard deviation/√n

Mean = 80

Standard deviation = 5

n = 400

z score for 95% confidence interval = 1.96

C.I = 80 ± 1.96 × 5/√400

C.I = 80 ± 1.96 × 5/20

C.I = 80 ± 1.96 × 0.25

C.I = 80 ± 0.490

Confidence Interval =

80 - 0.490

= 79.510

80 + 0.490

= 80.490

Confidence Interval: (79.510, 80.490)

d) As the sample size increases, the confidence interval for the lower class (bound) increases while that of the upper class(bound) decreases.

2a) The mean of a sample of 25 was calculated as ¯x=500. The sample was randomly drawn from a population with a standard deviation of 15.

For a,b and c the confidence interval formula above cannot be applied because n is less than 30, so we use the t score confidence interval value

C.I = Mean ± t score × Standard deviation/√n

a) Mean = 500

Standard deviation = 15

n = 25

Degree of freedom = 25 - 1 = 24

Hence, 99% confidence interval degree of freedom t score = 2.064

Hence, Confidence Interval =

500 ± 2.797 × 15/√25

500 ± 2.797 × 15/5

500 ± 2.797 × 3

Confidence Interval =

500 - 8.391

= 491.609

500 + 8.391

= 508.391

Confidence Interval: (491.609, 508.391)

b) Repeat part (a) changing the population standard deviation to 30

Hence, Confidence Interval =

500 ± 2.797 × 30/√25

500 ± 2.797 × 30/5

500 ± 2.797 × 6

500 ± 16.782

Confidence Interval =

500 - 16.782

= 483.218

500 + 16.782

= 516.782

Confidence Interval: (483.218, 516.782)

c) Repeat part(a) changing to the population standard deviation to 60.

Hence, Confidence Interval =

500 ± 2.797 × 60/√25

500 ± 2.797 × 60/5

500 ± 2.797 × 12

500 ± 33.564

Confidence Interval =

500 - 33.564

= 466.436

500 + 33.564

= 533.564

Confidence Interval: (466.436,533.564)

d)As the standard deviation increases, the confidence interval for the lower class (bound) decreases while that of the upper class(bound) increases.

Answer:

95%

Confidence levels range from 80% to 99%,with the most common confidence level being 95%.

Choosing a Confidence Level for a Population Sample.

Confidence Level z*-value

Answer:

I would say B.120 minutes

Answer:

4 hours is the answer

Step-by-step explanation:

If the Bartletts drive at the same average rate, today they must have derived for 4 hours.

Given that,
They drove a total of 550 miles in 11 hours. Today, they will drive another 200 miles and arrive at the park. If the Bartletts drive at the same average rate, how long will they drive today is to be determined.

Distance is defined as the object traveling at a particular speed in time from one point to another.

Here,
Speed = distance/time
Speed = 550 / 11  = 50 miles per hour
Again,
Speed = distance/time
50 = 200 / time
time = 4 hours,

Thus, If the Bartletts drive at the same average rate, today they must have derived for 4 hours.

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Given:

The expression is

[tex]\tan (\cos ^{-1}(-\dfrac{1}{2}))[/tex]

To find:

The value of given expression.

Solution:

We have,

[tex]\tan (\cos ^{-1}(-\dfrac{1}{2}))[/tex]

[tex]=\tan (\pi-\cos^{-1}(\dfrac{1}{2}))[/tex]          [tex][\because \cos^{-1}(-\theta)=\pi -\cos^{-1}\theta][/tex]

[tex]=\tan (\pi-\cos^{-1}(\cos \dfrac{\pi}{3}))[/tex]      [tex][\because \cos \dfrac{\pi}{3}=\dfrac{1}{2}][/tex]

[tex]=\tan (\pi-\dfrac{\pi}{3})[/tex]

[tex]=-\tan (\dfrac{\pi}{3})[/tex]                 [tex][\because \tan(\pi-\theta)=-\tan \theta][/tex]

[tex]=-\sqrt{3}[/tex]         [tex][\because \tan \dfrac{\pi}{3}=\sqrt{3}][/tex]

Therefore, the value of given expression is [tex]-\sqrt{3}[/tex].

Answer:

do not end urself please ur a good guy

Step-by-step explanation:

it's b not d

Answer:

multiple possibilities

Step-by-step explanation:

Y=5x

yx=5

it is unsolvable but have various possible answers:

y=5

x=1

(vise versa)

————

y=2.5

x=2

(vise versa)

Answer:

2/5

Step-by-step explanation:

You need to divide 1/4 by 5/8

Keep change flip- 1/4*8/5

the answer is 8/20

simplified- 2/5

decimal form- 0.4

[tex]\frac{5}{32}[/tex] [tex]many\ 1/4 \ cups\ servings\ are\ in\ 5/8\ cup.[/tex]

Division can be defined as the splitting of a large group into smaller groups such that every group will have an equal number of items. It is an operation used for equal grouping and equal sharing in math.

According to the question

Number of 1/4 cups servings are in 5/8 cup:

Based on the given conditions:

= [tex]\frac{5}{8} \div\frac{1}{4}[/tex]

= [tex]\frac{\frac{5}{8} }{\frac{1}{4} }[/tex]

= [tex]\frac{5}{8\times4}[/tex]

= [tex]\frac{5}{32}[/tex]

[tex]\frac{5}{32}[/tex] [tex]many\ 1/4 \ cups\ servings\ are\ in\ 5/8\ cup.[/tex]

Find out more information about division here

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Answer:

-690/1000

Step-by-step explanation:

Answer:

1.7

Step-by-step explanation:

1 + 7/10

= 1 + 0.7

= 1.7

Answer:

25

Step-by-step explanation:

1325 / 53 = 25

Answer:

how you gonna go out in a pandemic?

Step-by-step explanation:

unless you're in a place where the virus was handled properly, the understandable, have a nice day.

and uhh

communication is key to a healthy relationship

Answer:

Step-by-step explanation:

8x+2=3

8x=1

x=1/8

Answer:

C, D

Step-by-step explanation:

We can solve this graphically and analytically.

Graphically, looking at the attached image below, if we graph the two inequalities and plot the points, you can find the points which are solutions by finding the points in the overlapping area.

This obviously excludes A as it only appears in [tex]y \geq x+2[/tex]

C is included as y [tex]\geq x+2[/tex] includes the point on the line.

D is obviously a solution.

B is however not a solution because is lies on the line [tex]y = \frac{-5x}{2} - 3[/tex], which the inequality excludes.

Analytically, if we can find one of the two inequalities where it is not a solution, it is not a solution of the system.

A: (0, 0)

[tex]y \geq x+2\\0 \geq 0 + 2\\0 \geq 2\\false[/tex]

A is not a solution

B: (-2, 2)

[tex]y \geq x+2\\2 \geq -2 + 2\\2\geq 0\\true[/tex]

[tex]y > \frac{-5x}{2} -3\\2 > \frac{-5(-2)}{2} - 3\\2 > 5 - 3\\2 > 2\\false[/tex]

B is not a solution

C: (0, 2)

[tex]y \geq x+2\\2 \geq 0 + 2\\2 \geq 2\\true\\\\y>\frac{-5x}{2}-3\\2 > -3\\true[/tex]

C is a solution

D:

[tex]y \geq x + 2\\6 \geq -1 + 2\\6 \geq 1\\true\\\\y > \frac{-5x}{2} - 3\\6 > \frac{-5(-1)}{2} - 3\\6 > \frac{5}{2} - \frac{6}{2}\\6 > \frac{-1}{2}\\true[/tex]

D is a solution

Answer:

11/50

Step-by-step explanation:

22/100 can b reduced to 11/50 :)

Answer:

x>-2

Step-by-step explanation:

Answer:

[tex]x > - 2[/tex]

Step-by-step explanation:

hope u got it.

Answer:

For this equation there are infinite solutions.

Step-by-step explanation:

-2(6-3x)=-12+6x

-12+6x= -12 + 6x

-6                  -6

-12 = -12

0 = 0

Answer:

100

Step-by-step explanation: : )

.

Answer:

21.9

Step-by-step explanation:

Answer:

Step-by-step explanation:

y ≤ [tex]\frac{1}{2}[/tex] x - 4

Answer: The answer is (19, 17), (20, 18), (21, 19), (22, 20), and (23, 21).

Step-by-step explanation:

Step-by-step explanation:

Let the amount of money Andre has be $A.

Spending $10 on a book = A - 10

If you like to venture further, feel free to check out my insta (learntionary). I'll be constantly posting math tips and notes! Thanks!

Answer: Z= -9.5

Step-by-step explanation:

write the division as a fraction

-4.75=1/2Z

Multiply both sides of the equation by 2

-9.5=Z

then swap the sides of the equation

Z= -9.5

And if they are asking for fraction form then its either

Z= - 19/2, or Z= -9 1/2

Answer:

B, C, and E are correct

Step-by-step explanation:

Answer:

the answers are B, C, and E

Step-by-step explanation:

got it right on edge 2021 hope this helped! :]

Answer:

yes the square root of 144 is 12

Step-by-step explanation:

12 x 12 = 144 and 144 divided by 12 = 12

Answer:

5[tex]\sqrt{2}[/tex]

Step-by-step explanation:

Answer:

Youre correct

Step-by-step explanation:

Answer:

it is true

Step-by-step explanation: