# Question HelpA random sample of n measurements was selected from a population with unknown mean u and standard deviation o- 20 for each of the situations in parts a throughd. Calculate a 95% confidence interval for u for each of these situations.a. n 60, x= 32b. n 200, x=119C. n= 90, x=13d. n 90, x 4.59e. Is the assumption that the underlying population of measurements is normally distributed necessary to ensure the validity of the confidence intervals in parts athrough d? Explain.a.(Round to two decimal places as needed.)frect: 0?Enter your answer in the edit fields and then click Check AnswerCheck AnswerClear Al1=temaining10/Ware to searchasui44

Question
40 views help_outlineImage TranscriptioncloseQuestion Help A random sample of n measurements was selected from a population with unknown mean u and standard deviation o- 20 for each of the situations in parts a through d. Calculate a 95% confidence interval for u for each of these situations. a. n 60, x= 32 b. n 200, x=119 C. n= 90, x=13 d. n 90, x 4.59 e. Is the assumption that the underlying population of measurements is normally distributed necessary to ensure the validity of the confidence intervals in parts a through d? Explain. a. (Round to two decimal places as needed.) frect: 0 ? Enter your answer in the edit fields and then click Check Answer Check Answer Clear Al 1= temaining 10/ W a re to search asui 44 fullscreen
check_circle

Step 1

Note:

Hey, since there are multiple sub-parts question posted, we will answer first three sub-parts. If you want any specific sub-part question to be answered then please submit that sub-part question only or specify the sub-part question number in your message.

Step 2

a. Computation of 95% confidence interval for the population mean for n=60, x-bar=32:

Here, x-bar=32; standard deviation is σ=20; and n=60.

Step-by-step procedure to find the 95% confidence interval for the population mean using ti-84 calculator:

• Enter STAT > TESTS > 7: Z Interval…
• Choose Inpt:Stats.
• Enter σ=20, x-bar:32, n:60, and C-Level:.95.
• Click on Calculate.

Thus, the output obtained as (26.939, 37.061).

Therefore, the 95% confidence interval for µ for n=60, x-bar=32 is (26.939, 37.061).

Step 3

b. Computation of 95% confidence interval for the population mean for n=200, x-bar=119:

Here, x-bar=119; standard deviation is σ=20; and n=200.

Step-by-step procedure to find the 95% confidence interval for the population mean using ti-84 calculator:

• Enter STAT > TESTS > 7: Z Interval…
• Choose Inpt:Stats.
• Enter σ=20, x-bar:119, n:200, and C...

### Want to see the full answer?

See Solution

#### Want to see this answer and more?

Solutions are written by subject experts who are available 24/7. Questions are typically answered within 1 hour.*

See Solution
*Response times may vary by subject and question.
Tagged in

### Other 