An industrial designer wants to determine the average time it takes for an adult to assemble a toy. 24 people were randomly chosen to assemble the toy and the time taken (in minutes) were as follows: 17, 13, 18, 19, 17, 21, 29, 22, 16, 28, 21, 15 26, 23, 24, 20, 8, 17, 17, 21, 32, 18, 25, 22; Using interval estimate to infer the population mean with a 95% confidence level

tuzkutimonq4

tuzkutimonq4

Answered question

2022-09-04

An industrial designer wants to determine the average time it takes for an adult to assemble a toy. 24 people were randomly chosen to assemble the toy and the time taken (in minutes) were as follows:
17, 13, 18, 19, 17, 21, 29, 22, 16, 28, 21, 15 26, 23, 24, 20, 8, 17, 17, 21, 32, 18, 25, 22
Using interval estimate to infer the population mean with a 95% confidence level

Answer & Explanation

lloviznennj

lloviznennj

Beginner2022-09-05Added 12 answers

Step 1
Actually, what you denoted as the sample variance is in fact the sample standard deviation s = 5.363. The 95% confidence interval is given by
[ x ¯ t 0.025 , 23 s n , x ¯ + t 0.025 , 23 s n ] .
We need to use 0.025 = 0.05 2 because this is a two-tailed test. Looking the value of t 0.025 , 23 up in a table, we find t 0.025 , 23 = 2.069 . Hence the LCL is equal to 20.375 2.069 5.363 24 = 18.11 , and the UCL is equal to 20.375 + 2.069 5.363 24 = 22.64 .

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?