MATH 225 Week 8 Final Exam
Student Name Chamberlain University MATH-225 Statistical Reasoning for the Health Sciences Prof. Name Date Question 1: Is it reasonable to use the line of best fit to predict time spent with family based on video game time? Given the line of best fit y^=−0.27x+57.5\hat{y} = -0.27x + 57.5, the predicted number of minutes spent with family when someone plays video games for 95 minutes is 31.85 minutes. Since this value lies within the range of the original data and assumes a strong linear relationship, the prediction is considered both reliable and reasonable. Correct Answer: The estimate, a predicted time of 31.85 minutes, is both reliable and reasonable. Question 2: Which of the following are feasible equations for a least squares regression line? To determine the appropriate equations for a regression line, we should look for equations with plausible slopes and intercepts that represent a potential trend over time. In this context, acceptable equations for population change include: The equation y^=−38,000+2500x\hat{y} = -38,000 + 2500x is not feasible due to the negative intercept. Correct Answers: Question 3: Which group receives the placebo? In the given experiment, the group that received the substance with no therapeutic effect is considered the placebo group. A placebo is used as a control to compare the effects of the actual medication. Correct Answer: The group that received the drug with no therapeutic effect. Great! I’ll continue rephrasing the exam questions and answers in paragraph format, keeping the original question titles, and using row-column tables where necessary. Let’s proceed with the next set. Question 4: What are the correct null and alternative hypotheses for Becky’s coin flip experiment? Becky flipped a coin 30 times and obtained heads 18 times. To determine if the proportion of heads is different from 0.5, she needs to perform a two-tailed hypothesis test. The null hypothesis should state that the proportion p=0.5p = 0.5, and the alternative hypothesis should state that p≠0.5p \neq 0.5, indicating a possible deviation in either direction from fairness. Correct Answer: H0:p=0.5;Ha:p≠0.5H_0: p = 0.5; H_a: p \neq 0.5, which is a two-tailed test. Question 5: Is the farmer’s study observational or experimental, and what is the controlled factor? The farmer divided his land into four equal sections with similar soil conditions and planted the same crop, monitoring yields over four weeks. Since the farmer controlled land division and the planting conditions, this qualifies as an experiment. Among the listed options, the land was the manipulated factor. Correct Answer: The study is an experiment. The controlled factor is the land. Question 6: What is the minimum sample size required to estimate the mean within 2 inches with 95% confidence? Given a population standard deviation of 3.7 inches and a 95% confidence level, the minimum required sample size nn can be calculated using the formula:n=(z⋅σE)2n = \left( \frac{z \cdot \sigma}{E} \right)^2Using a z-score of 1.96 for 95% confidence, the required sample size is approximately 14. Correct Answer: 14 dog heights. Question 7: What is the Type I error in the apartment affordability scenario? In this scenario, the null hypothesis claims that Jacob earns enough to afford a luxury apartment. A Type I error occurs if Jacob wrongly rejects this hypothesis—believing he can’t afford the apartment when he actually can. Correct Answer: Jacob thinks he does not earn enough money to afford the luxury apartment when, in fact, he does. Question 8: Which normal distribution has the smallest standard deviation? When comparing multiple normal curves on the same graph, the distribution with the narrowest bell shape has the smallest standard deviation. Distribution B appears most concentrated around the mean. Correct Answer: B Question 9: What is the level of measurement for the patient’s temperature data? The doctor records the patient’s temperature every hour. Temperature data measured in degrees Fahrenheit is quantitative and can have meaningful intervals but no true zero, placing it on the interval level of measurement. Correct Answer: Interval Question 10: What is the median truck price? Given the list of prices in thousands—20, 46, 19, 14, 42, 26, 33—when ordered, the median value (middle value) is 26. Correct Answer: Median = 26 thousand dollars. Question 11: What is the mode for the number of cards drawn until a queen appears? The list of cards drawn is: 3, 12, 3, 11, 5, 5, 3, 10, 12. The number 3 appears most frequently, making it the mode. Correct Answer: Mode = 3 cards. Question 12: What does the histogram suggest about the data distribution? Based on the histogram (not shown here but referred to in the question), if one tail appears longer than the other, it indicates skewness. If both sides are roughly balanced, it is symmetrical. Correct Answer: The data are symmetric. Question 13: Which hypothesis tests are left-tailed? Left-tailed tests have alternative hypotheses indicating values less than the null hypothesis value (e.g., Ha:X<μH_a: X < \mu). Among the choices: Correct Answer: Question 14: What are the correct null and alternative hypotheses to determine if 53% of people prefer Product A? To test whether 53% of people prefer Product A, the null hypothesis should state p=0.53p = 0.53. Since the question checks if the actual proportion differs, the alternative should be p≠0.53p \neq 0.53, a two-tailed test. Correct Answer: H0:p=0.53;Ha:p≠0.53H_0: p = 0.53; H_a: p \neq 0.53 Question 15: Which hypothesis test is right-tailed? Right-tailed tests have the alternative hypothesis indicating a value greater than the null (e.g., Ha:X>μH_a: X > \mu). Correct Answer: Question 16: Construct a frequency table for DVDs rented using four classes Data provided:15, 31, 28, 19, 14, 18, 28, 19, 10, 19, 10, 24, 14, 18, 24, 27, 10, 18, 16, 23 Here is the grouped frequency table: Lower Class Limit Upper Class Limit Frequency 10 15 6 15 20 6 20 25 4 25 31 4 MATH 225 Week 8 Final Exam Question 17 The bar graph below shows the number of boys and girls in different classes.What is the number of boys in the class with the highest count? According to the graph (not shown here), the class with the highest number of boys has 23 boys. MATH 225 Week 8 Final Exam Class Number of Boys Number of