1.3 solutions

# Give an estimate use 997 rule aka empirical rule

This preview shows pages 1–3. Sign up to view the full content.

95% of the math scores lie between what two values? (Give an estimate ) Use the 68-95-99.7 Rule (aka Empirical Rule). About 95% of the scores lie within 2 standard deviations of the mean. That means 95% of the math scores lie between 70-2(10) and 70+2(10) = 50 and 90. i. Bob scores 85 on each exam. On which exam did he perform better, compared to his classmates? Compare Z scores on the two exams. From part b, Bob’s Z score on the math exam is 1.5. On the stat exam, Bob’s Z score is = 1.0. Bob did better on the math exam. 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2. Data are collected on the fuel economy of 2001 model midsize cars. The information measured in average miles per gallon (MPG) is summarized below. MPG Frequency 32 30 28 26 24 22 7 6 5 4 3 2 1 0 Histogram of MPG Descriptive Statistics: MPG Total Variable Count Mean StDev Minimum Q1 Median Q3 Maximum MPG 32 26.750 2.874 22.000 24.000 26.500 28.750 33.000 Can the 68-95-99.7 rule be applied to this data to give an approximate range where 95% of the MPG lie? Explain why or why not. No; data are not close to a normal distribution 3. Bob’s Z-score on a psychology exam is 0.25. What is the correct interpretation? a. Bob’s score is at the 25 th percentile. b. Bob got a 25 on the exam. c. Bob’s score is 25 percentage points above the mean. d. Bob’s score is 0.25 standard deviations above the mean.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern