QN 2 A student wants to estimate the mean amount of money sp

Q.N. 2) A student wants to estimate the mean amount of money spent. by college students on books this semester. He surveys 50 randomly chosen students and calculates a sample mean of x = $ 235 and standard deviation of $75. Calculate a 95% confidence interval of the population mean.

Solution

Let the sample size=50,sample mean=$235,Standard deviation=$75.

Using MINITAB to find the Confidence interval.

MINITAB procedure.

To calculate a confidence interval and perform a hypothesis test for a single population proportion , have summarized data:

The output is obtained as follows,

Test and CI for One Proportion

Sample   X      N     Sample p         95% CI
1        50   235 0.212766      (0.160440, 0.265092)

Using the normal approximation.

The 95% confidence interval of population mean is (0.160440, 0.265092).