## Description

1. You wish to know the average GPA of MBA students. Compute the 95% confidenc

You wish to know the proportion of MBA students that are majoring in Finance.

2. Compute the 95% confidence interval of the proportion using the sample of 200 students. Describe your findings.e interval of the mean using the sample of 200 students. Describe your findings.

3 .You wish to learn the average age of an MBA student within 2 years and with 99% confidence. How large of a sample should you get?

4. You wish to learn the proportion of MBA students that are female within 3%, and with 98% confidence. How large of a sample should you get?

Access the data file from Dr. M's website**. Don't use the link that is provided in the Complete assignment!** Dr. M's data file is a little different from the one that is in the Complete assignment. Dr. M's is the one that is up to date. Here's the biggest difference: when you do the Complete assignments the coding for gender is 0=MALE, 1=FEMALE. Always use this coding.

## Explanation & Answer

I cannot go on with the work without the data file

Hi,Find attached the completed work.Feel free to ask for any clarification or editing if need be.Looking forward to working with you in future.Thank you.

Running head: CONFIDENCE INTERVALS

Confidence Intervals

Student’s Name

Professor’s Name

Course Title

Date

CONFIDENCE INTERVALS

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For these problems, the sample size of the data used is 200. Data has been obtained from

Dr. M’s website and the calculations are contained in the supporting excel file with four

spreadsheets. Each question is done on a separate sheet.

1. You wish to know the average GPA of MBA students. Compute the 95% confidence

To be 95% confident of the average GPA of MBA students, the confidence interval of the

mean of the sample provided has to be calculated. According to Mirabella (2011), the confidence

interval is calculated by adding or subtracting a margin of error from the sample mean (p. 3-5).

For this problem, the Z score (1.96) is multiplied by the standard deviation (0.31) and finally

divided by the sample square root to get the standard error of the mean (0.043). To get the

confidence interval, we subtract or add the standard of error to the mean (3.42) to get the upper

and lower bound estimates (3.38 and 3.46) respectively. It can thus be concluded that we are

95% confident that the average GPA of the MBA students lies between 3.38 and 3.46.

2. You wish to know the proportion of MBA students that are majoring in Finance. Compute the

95% confidence interval of the proportion using the sample of 200 students. Describe your

findings. e interval of the mean using the sample of 200 students. Describe your findings.

The aim of this question is to establish the proportion of students that are taking Finance

as a major at 95% confidence level. To get the sampling error, the z score is multiplied by the

standard error of proportion. The proportion of MBA students taking Finance according to this

sample is 0.275 obtained by taking the total number of finance students (55) divided by the

sample (200). The standard error of proportion is obtained through the excel formula

=(SQRT(0.275*(1-0.275)/200)). The result (0.031) is multiplied by the standard deviation to get

the sampling error that is later multiplied by the 95% confidence coefficient (1.96). The resulting

CONFIDENCE INTERVALS

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value (0.62), the sampling error is added or subtracted from the proportion of MBA students

taking Finance (0.275) to get the upper and lower bounds (0.34 and 0.21) respectively. It can

then be concluded that we can be 95% confident that the proportion of MBA students that are

majoring in finance lies between 21% and 34%.

3. You wish to learn the average age of an MBA student within 2 years and with 99% confidence.

How large of a sample should you get?

To begin with, the standard deviation of the ages in the sample provided which is (8.93).

The confidence coefficient of 99% is 2.57. With the confidence coefficient and the standard

deviation, the sample size can be calculated using the function [(z*s)/e]2 where z and s are the

confidence coeffici...