Problem Set - Assignment Example

PROBLEM SET WEEK INSTRUCTIONS: For each of the questions there is only one choice. Click in the check box to register the best answer. When complete, post this document to your Individual Forum by Day 7. Four histograms are displayed below. For each item, match the description to the appropriate histogram Histogram 1 Histogram 2 Histogram 3 Histogram 4 1. A distribution for a set of quiz scores where the quiz was very easy is represented by: A. Histogram I B. Histogram 2 C. Histogram 3 D.

Histogram 4 The next three questions refer to the following situation: A drug company developed a new formula for their headache medication. To test the effectiveness of this new formula, 250 people were randomly selected from a larger population of patients with headaches. 100 of these people were randomly assigned to receive the new formula medication when they had a headache, and the other 150 people received the old formula medication. The time it took, in minutes, for each patient to no longer have a headache was recorded.

The results from both of these clinical trials are shown below. The following present statements made by three different statistics students. For each statement, indicate whether you think the student's conclusion is valid. 2. The old formula works better. Two people who took the old formula felt relief in less than 20 minutes, compared to none who took the new formula. Also, the worst result - near 120 minutes - was with the new formula A. Valid B. Not valid 3. The average time for the new formula to relieve a headache is lower than the average time for the old formula.

I would conclude that people taking the new formula will tend to feel relief about 20 minutes sooner than those taking the old formula. A. Valid B. Not valid 4. I would not conclude anything from these data. The number of patients in the two groups is not the same so there is no fair way to compare the two formulas. A. Valid B. Not valid Next three questions refer to the following situation: The two boxplots below display final exam scores for all students in two different sections of the same course.

Section 1 Section 2 5. Which section would you expect to have a greater standard deviation in exam scores A. Section 1 B. Section 2 C. Both sections are about equal. D. It is impossible to tell. 6. Which data set has a greater percentage of students with scores at or below 30 A. Section 1 B. Section 2 C. Both sections are about equal. D. It is impossible to tell. 7. Which section has a greater percentage of students with scores at or above 80 A. Section 1 B. Section 2 C.

Both sections are about equal. 8. A baseball fan likes to keep track of statistics for the local high school baseball team. One of the statistics she recorded is the proportion of hits obtained by each player based on the number of times at bat as shown in the table below. Which of the following graphs gives the best display of the distribution of proportion of hits in that it allows the baseball fan to describe the shape, center and spread of the variable, proportion of hits A. B. C. D. Reasons: For item No.

6: The percentage of scores having 30 or below is about half of the lower 25% as the box both for section 1 and 2 as shown in their respective boxplot. For item No. 7 The same as in No. 6. Since 80 is the median score the upper 50% are having scores 80 and above for both sections. For item No. 8 The best presentation is plotting the percentage of hits to the number of players who made it. Graph C best represents the trend. It tells how many students make the highest percentage hits, and so on and so forth.