Chapter 03 Post Test

Looking at the table in Question 3, what is the mean?

38.67

If the teacher in the question above decided to divide each score in half rather than add the bonus points, what would be the new mean?

43

In Question 1, what is the mean?

5.37

What is the mode of the following list of scores: 5, 5, 5, 3, 6, 6, 6, 6, 6, 6, 6, 8, 8, 8, 8, 9, 9, 2, 2, 5, 5, 2, 2, 7, 8, 7, 7, 7, 7, 7, 3, 3, 5, 5, 5, 5, 7, 7, 3, 3, 3, 3, 3, 6, 6, 6, 6, 7, 8, 8, 8, 8?

6

A teacher collects exams from two classes. She finds the first class (n = 15) has a mean score of 83 and the second class (n = 25) has a mean score of 79. What is the weighted mean of these two classes?

80.5

Due to wanting students to know the importance of the final project in their class, a professor at a local college decides to give more weight toward the final project. While students can still earn only a total of 100 points from a final exam, homework, and the final project, the assignments are weighed (in order) from 40%, 10%, and 50%. Wanting to do well, a student scores an 83 on the final, 76 on the overall homework, and a 92 on the final project. What was the student's grade in the class?

86.8

A teacher is entering her student's exam score into an online gradebook. After calculating the mean (M = 86), she remembers that each student had turned in an assignment for 5 bonus points added to their overall exam score. If she adjusts each student's score, what is will be the new mean?

91

The mean describes data that are positively skewed.

False

A psychologist records the number of bar presses by a group of rats (N = 8) to receive food. This is only a portion of rats the researcher is interested in testing. The psychologist records the following number of bar presses: 5, 3, 8, 2, 9, 7, 4, and 5. What type of mean should the psychologist compute?

Sample mean

The mean and median tend to be at the center of bimodal distributions.

Treu

A normal distribution is sometimes referred to as a Gaussian distribution.

True

Summing the squared difference of each score from its mean produces a minimal solution.

True

The median is used to describe an ordinal scale of measurement.

True

The mode is the only central tendency that has a zero point.

True

Looking at the graph below, what type of modal distribution summarizes the data? What is the mean/median?

bimodal, 2

A college professor is having a problem entering student's grades into an online gradebook. At first, he calculates the mean to be 78; however, he notices that he is missing a score of 89. Once he inputs this value, the mean is now 82. He then notices that he put two of the same score of 82, so he deletes one and then adds the proper score of 76. Finally, he believes his gradebook is in order. Throughout this process, in what ways did the mean change?

increased, no change, decreased

A grade school teacher measures the height (in inches) of her students for a class project. The scores of her 12 students are 45, 41, 47, 41, 43, 41, 40, 42, 48, 39, 47, and 72. Which measure of central tendency is most appropriate for describing these data?

median

The who's who of yelp wants to rank local restaurants. Based on this scale of measurement, which measure of central tendency is most appropriate for describing the data?

median

What type of modal distribution can we infer from the following list of scores: 5, 5, 5, 3, 6, 6, 6, 6, 8, 8, 8, 9, 9, 2, 2, 5, 5, 2, 2, 7, 8, 7, 7, 7, 7, 7, 3, 3, 5, 5, 5, 7, 7, 3, 3, 3, 3, 3, 6, 6, 6, 6, 8, 8, 8, 8?

multimodal

Looking the table below, what type of mean can we infer will be calculated?

weighted mean