Use the given degree of confidence and sample data to construct a confidence interval for the population mean $\mu$ . Assume that the population has a normal distribution.
-A sociologist develops a test to measure attitudes towards public transportation, and 27 randomly selected subjects are given the test. Their mean score is 76.2 and their standard deviation is 21.4. Construct the 95%
Confidence interval for the mean score of all such subjects.
A) $74.6

Question

Use the given degree of confidence and sample data to construct a confidence interval for the population mean $\mu$ . Assume that the population has a normal distribution.
-A sociologist develops a test to measure attitudes towards public transportation, and 27 randomly selected subjects are given the test. Their mean score is 76.2 and their standard deviation is 21.4. Construct the 95%
Confidence interval for the mean score of all such subjects. 
A) $74.6 < \mu < 77.8$
B) $64.2 < \mu < 88.2$
C) $69.2 < \mu < 83.2$
D) $67.7 < \mu < 84.7$

Quizplus · Accepted Answer

The confidence interval is:$$76.2 \pm 1.96 	imes \frac{21.4}{\sqrt{27}} = 76.2 \pm 8.5$$$$= (76.2 - 8.5, 76.2 + 8.5) = (67.7, 84.7)$$

Use the Given Degree of Confidence and Sample Data to Construct