# Confidence Intervals and Sample Sizes, assignment help

**Use the Student_Data.xls file which consists of 200 MBA students at Whatsamattu U. The file includes variables regarding students’ age, gender, major, GPA, Bachelors GPA, course load, English speaking status, family, weekly hours spent studying. **

**COMPLETE PROBLEM 1:** Let’s assume (for this problem only) that the Student_Data.xls file was the entire population. We know the mean and standard deviation of student ages to be 42.3 and 8.9, respectively. Using the Normal_ Probability.xls file:

a) compute the percentage of students that are older than 50,

b) compute the percentage of students that are younger than 40,

c) compute the percentage of students that are between 41 and 46, inclusive.

d) compute the age range of the oldest 10% of the students.

Then compare each of the answers you computed to the truth as found in the actual file. Briefly discuss your results (100+ words, 3 or more sentences).

Complete Problem #1: Use the **normal probability stat file** to calculate this problem. Use the **first sheet at the bottom that says Normal**. You should be able to get all answers from that sheet. Copy and paste the output chart with answers. Do not worry about calculating the “real truth” as instructions requested. I am only looking for the answers from the file on this one.

**COMPLETE PROBLEM 2:** You wish to know the average GPA of MBA students at Whatsamatta U. Compute the 95% confidence interval of the mean using the sample of 200 students. Report on your findings (50+ words, 2 or more sentences) along with a normal probability chart that illustrates the points raised in your report.

Complete Problem #2: Use the **Confidence Interval stat file** to calculate this problem. Use the **second sheet on the bottom** which allows you to copy and paste your raw data into the file for it to calculate. Copy and paste the output chart as well as the bell curve that is underneath the output chart that is the normal prob chart for which the instructions are asking.

**COMPLETE PROBLEM 3:** 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. Report on your findings (50+ words, 2 or more sentences) along with a normal probability chart that illustrates the points raised in your report.

Complete Problem #3: Use the **Confidence Interval stat file**, the sheet at the bottom for **proportion** (sheet 3). You can’t copy and paste raw data here. You must count the number of successes by sorting the student data file by major and counting the # of Finance majors. Copy and paste the relative charts here as you did in #2.

*****note: Please follow all directions as instructed I provided the files needed, let me know if you have troubles opening sheets. **