Pre-Test Unit 9: Descriptive Statistics

Transcription

1 Pre-Test Unit 9: Descriptive Statistics You may use a calculator. The following table shows how many text messages different students sent this week. Answer the following questions using the table Construct a histogram for the above data set using appropriate scale for the axis and appropriate axis intervals for the frequency. (8 pts; 2 pts for axis scale and label, 2 pts for axis intervals and label, 4 pts for correct frequencies) 2. Construct a box and whisker plot for the above data set in the blank space above. (8 pts; 2 pts for quartiles, 2 pts for end points, 2 pts for number line labels, 2 pts for box/whisker) 3. What are the mean and median of the above data set? (4 pts; 2 pts each) 4. What are the range and interquartile range of the above data set? (4 pts; 2 pts each) 5. What is the population standard deviation of the above data set? (4 pts; no partial credit) 6. What can you tell about a data set of test scores with a mean of 75%, median of 78%, range of 30%, and population standard deviation of 7%? (4 pts; partial credit at teacher discretion) 7. What could be a mean and median of a data set of test scores where a third of the class failed, but the rest of the class scored above an 80%? Justify each choice in writing. (4 pts; partial credit at teacher discretion) 337

2 Construct a scatter plot for the following data set using appropriate scale for both the and axis. (8 pts; 1 pts for each axis scale/interval, 1 pt for deciding to break each axis or not, 2 pts for correct independent/dependent axes, 2 pts for correctly plotted points) 8. This table shows the number of hours students slept the night before their math test and their scores. Hours Slept Test Score Anna 8 95 Bob 7 90 Carly 8 85 Damien 6 75 Esther 5 65 Franco 8 90 Georgia 8 80 Hank 9 95 Innya 7 80 Jacob 6 70 Use the following scatter plot to answer each question. The scatter plot shows the monthly income of each person in hundreds of dollars versus the percent of their income that they save each month. (4 pts; 2 pts for correct answer with no explanation) 9. What patterns or associations do you see present in this data? Why do you think so? Kory Percent of Income Saved Rachel Nancy Paul Lexi Tanya Mike Quinn Stan Oliver Monthly Income in Thousands of Dollars 10. Which person makes the most money per month? How much do they make? 338

3 Draw an informal function of best for the given scatter plots. (3 pts; partial credit at teacher discretion) 11. This scatter plot shows the amount copper in water in ppm versus plant growth in cm over three months. 12. This scatter plot shows the hours a cubic foot of ice was exposed to sunlight versus the thickness of ice that melted in inches. Plant Growth Ice Melted Plant Growth in cm Copper in Water in ppm Thickness of Ice Melted in inches Hours of Sunlight Exposure Explain why the drawn line of best fit is accurate or why not. (3 pts; partial credit at teacher discretion) 13. This scatter plot shows the age in years versus the height in inches of a group of children. 14. This scatter plot shows the hours of TV watched per week versus the GPA on a 4.0 scale for a group of students. Height Age GPA Hours Weekly TV 339

4 The scatter plot shows what people think the temperature feels like ( axis) as the humidity ( axis) varies when the room is actually at 68 F. The equation of the line of best fit is. (4 pts; 2 pts for equation answer, 2 pts for graph answer) Feels Like Temp 15. Predict what a person would say the temperature feels like when the humidity is at 80% using both the equation and graph. Equation Work: Graph Prediction: % Humidity Using the same scatter plot and equation of the line of best fit of, answer the following questions. (2 pts; partial credit at teacher discretion) 16. What does the slope of this equation mean in terms of the given situation? In other words, explain what the rise and run mean for this problem. 17. What does the intercept of this equation mean in terms of the given situation? In other words, explain what the intercept means when considering the humidity and feels like temperature. Answer the following questions. (4 pts; partial credit at teacher discretion) 18. A function of best fit has a correlation coefficient of R What does that tell us? 19. Plot the two sets of residuals on number lines. (4 pts; 2 pts each) x x Anne s Bob s

5 20. Which person s line of best fit works better and why do you think so? (4 pts; 2 pts for answer, 2 pts for explanation) Answer the following questions about two way tables. (4 pts; partial credit at teacher discretion) 21. Construct a two way table from the following data about whether people are democrats or republicans and whether or not they support stricter gun control laws. Democrat or Republican? Support Strict Gun Control? D R R R D D R D D D R D R R D R D D R R Y N N N N Y N Y Y Y N Y N Y N N Y Y Y N 22. Do you think there is a relationship between party affiliation and gun control laws? Based on the data, why or why not? (no credit without explanation of why, partial credit at teacher discretion for explanation) Answer the following questions using the given two way table. (4 pts; no partial credit) Support School Uniforms Do Not Support School Uniforms Students Teachers How many students were surveyed? 24. As a percent to the nearest hundredth (two decimal places) what is the relative frequency of students who support school uniforms? 341