Question

Software instruction: A hybrid course is one that contains both online and classroom instruction. In a study performed at Middle Georgia State College, a software package was used as the main source of instruction in a hybrid college algebra course. The software tracked the number of hours it took for each student to meet the objectives of the course. In a sample of

42

students, the mean number of hours was

80.9

, with a standard deviation of

51.2

.

(a) Construct a

90%

confidence interval for the mean number of hours it takes for a student to meet course objectives. Round the answers to one decimal place.

A

90%

confidence interval for the mean number of hours it takes for a student to meet the course objectives is

Answer 1

Ans.)

Explanation:

Given:

The provided sample mean is and the sample standard deviation is s = 51.2. The size of the sample is n=42 and the required confidence level is 90%

The number of degrees of freedom is df=42−1=41, and the significance level is α=0.1.

Based on the provided information, the critical t-value forα=0.1 and df=41 degrees of freedom is tc​=1.683.

To find critical value we use excel abs(T.INV(0.1/2,41)) gives tc = 1.683

The 90% confidence for the population mean \muμ is computed using the following expression

Therefore, based on the information provided, the 90 % confidence for the population mean μ is