Please answer everything i just guessed! thank you In a random sample of 55 refr
ID: 3176049 • Letter: P
Question
Please answer everything i just guessed! thank you
In a random sample of 55 refrigerators, the mean repair cost was $141.00 and the population standard deviation is $19.30. A 95% confidence interval for the population mean repair cost is (135.90, 146.10). Change the sample size to n = 110. Construct a 95% confidence interval for the population mean repair cost. Which confidence interval is wider? Explain. Construct a 95% confidence interval for the population mean repair cost. The 95% confidence interval is (1, 1). (Round to two decimal places as needed.) Which confidence interval is wider? Explain. Choose the correct answer below. The n = 55 confidence interval is wider because a smaller sample is taken, giving less information about the population. The n = 110 confidence interval is wider because a larger sample is taken, giving more information about the population. The two intervals are the same size because the confidence interval is based on the level of confidence and sample standard deviation.Explanation / Answer
For n = 110,
Statistical software output for 95% confidence interval is:
One sample Z confidence interval:
: Mean of population
Standard deviation = 19.3
95% confidence interval results:
Hence,
The 95% confidence interval for the population mean repair cost is:
(137.39, 144.61)
We can see from both the confidence interval that confidence interval for n = 55 is wider. Hence,
Option A is correct.
Mean n Sample Mean Std. Err. L. Limit U. Limit 110 141 1.8401828 137.39331 144.60669