PSY 211 chap 2

In the following stem and leaf display, how many scores are in the 40's? 1 44444 3 22 6 1 7 333 9 44

0

For a complete frequency distribution, what is ?

1

Given the following frequency table, which way is not correct for calculating ΣX? X F 1 4 2 1 3 2 4 2

1 + 2 + 3 + 4

If you are given the following stem and leaf display and asked to construct a frequency distribution chart, what would be the width of the intervals? 1 332 2 45 3 1157 4 231 5 221

10

Weights of birds were collected and organized into the following frequency distribution table. Use interpolation to estimate the percentile rank for X = 27. X C% 34-39 100% 30-34 71% 25-29 32% 20-24 12%

22%

Given the following distribution of scores, which percentile would require interpolation to estimate the values? X C CF 15-19 27 100 10-14 32 73 5-9 22 41 0-4 19 19

30

For the scores shown in the steam and leaf display, what is the lowest score? 2 5213 4 234 6 25 8 913 8 88239

31

In a data set the minimum element is 23, the maximum is 62, and the determined width is 4. Which of the following will not be an interval in the grouped frequency table?

32-36

A set of scores ranges from a high of X = 75 to a low of X = 23. If the bottom interval in a frequency table is 18-23, what is the top interval?

72-77

If X = 45 has a percentile rank of 75%, which of the following is true?

75% of the scores in the set are at or below 45.

In the following stem and leaf display, there is a missing stem marked with a "?". The range of the scores is supposed to be 53. What is the missing stem? 4 203 6 0021 ? 213

9

A survey asked families to report on the number of cars they own. The following is the frequency table for the results. x f 1 125 2 101 3 ?

If the proportion of families with 1 car is 50%, find the number of families with 3 cars. 24

The following is a collection of test scores presented as a grouped frequency table X F 20-27 7 28-35 8 36-43 6 44-51 4

What is the 60th percentile? b. 35.5

Four species of insects around a pond are being studied. The initial phase of the study involves capturing and counting members of the species. The four species are labeled A, B, C, and D. If these values are presented in a frequency distribution graph, what kind of graph would be appropriate?

a bar graph

What would be the most appropriate way to display a graph of a population's IQ scores?

a smooth curve

On a quiz, the possible points are 0, 1, 2, 3, and 4. The following is the classroom set of scores on the quiz: Which of the following best describes this set of scores? 0 0 0 1 1 1 1 2 2 2 2 2 2 3 3 3 3 4 4 4

symmetrical

The following frequency distribution table represents test scores for a class of students. How many students scored less than 70? X F 61-68 2 69-76 6 77-84 12 85-92 5 93-100 1

It cannot be determined.

Jerilyn calculated the percentages in a frequency table to be the following: 10%, 20.3%, 10%, 61.2%, and 24%. Which of the following is a true statement?

Jerliyn cannot be correct because her percentages add to more than 100%.

In a study measuring the number of books read in a month, a group of data ranging from 0-6 is shown in a histogram. If the bars in the histogram gradually decrease in height from left to right, what can you conclude about the data set?

There are more people reading lower numbers of books than higher numbers.