Unit 5 check

Unit 5 check: Regression Analysis

10 questions from 5 lessons in Unit 5. Answer each one, and if you miss, follow the link back to where it is taught, then try again. Your score counts first tries.

Question 1 · from 5.1 · Multiple choice

A nutritionist wants to know whether the grams of sugar in a breakfast cereal can be used to predict its calories per serving. She has both measurements for 40 cereals. Which graph should she make?

Question 2 · from 5.2 · Multiple choice

A study of 32 apartments near a university finds $r = - 0.58$ between distance from campus (miles) and monthly rent (dollars). Which interpretation is correct?

Question 3 · from 5.3 · Calculate

A pet store models a hamster's weight (grams) from its age (weeks), using hamsters 3 to 12 weeks old: $\hat{y} = 22.5 + 9.4 x$ . What weight does the model predict for an 8-week-old hamster? Give your answer in grams.

Your answer

Question 4 · from 5.4 · Calculate

The regression line for predicting a used laptop's resale price (dollars) from its age (months) is $\hat{y} = 612 - 11.5 x$ . A 24-month-old laptop sold for 380 dollars. Find its residual, in dollars.

Your answer

Question 5 · from 5.5 · Multiple choice

Each model below was fit to the data described. For which model does the y-intercept have a reasonable interpretation in context?

Question 6 · from 5.1 · Multiple choice

A scatterplot of 25 students' hours of sleep the night before a test (x) and their test scores (y) shows points that drift upward from left to right, with a lot of scatter around that trend. Which description fits?

Question 7 · from 5.2 · Multiple choice

A biologist finds $r = 0.74$ between the length and weight of 40 salmon, with length in inches and weight in pounds. She converts every length to centimeters and every weight to kilograms, then recomputes. What is the new correlation?

Question 8 · from 5.3 · Multiple choice

A pediatrician's model predicts a child's height (inches) from age (years), using children aged 2 to 10: $\hat{y} = 31.6 + 2.5 x$ . A parent substitutes her own age, 40. Which statement is correct?

Question 9 · from 5.4 · Multiple choice

A teacher's model predicts a student's score on a 30-point quiz from the number of minutes the student studied: $\hat{y} = 4.2 + 0.85 x$ . Dana studied for 20 minutes, and her residual was 1.8 points. What was Dana's actual score?

Question 10 · from 5.5 · Multiple choice

A model predicts a car's highway gas mileage (miles per gallon) from its weight (thousands of pounds). For this model, $r^{2} = 0.72$ . Which is the correct interpretation?

0 of 10 answered.