Q: Which of the following statements about relative frequency is correct?

Relative frequency is calculated as $\text{frequency} \div N$ and ranges from $0$ to $1$.

Question 1

Which of the following best describes the primary purpose of data summaries in psychological research?

Accepted Answer

To simplify complex data into interpretable metrics that reveal trends and facilitate communication.

Question 2

A researcher collects the following ages from a sample: 19, 20, 19, 21, 19, 19, 20. What is the value of $N$ for this dataset?

Accepted Answer

$N = 7$

Question 3

Given the dataset: 19, 19, 20, 20, 20, 21, 15, what is the frequency of the value 20?

Accepted Answer

3

Question 4

If a frequency distribution table shows that the relative frequency of age 20 is $0.30$ in a sample of $N = 10$, how many participants are age 20?

Accepted Answer

3

Question 5

Which of the following statements about relative frequency is correct?

Accepted Answer

Relative frequency is calculated as $	ext{frequency} \div N$ and ranges from $0$ to $1$.

Question 6

A cumulative frequency table is constructed from the following frequencies for ages: 18 (1), 19 (4), 20 (3), 21 (1). What is the cumulative frequency for age 20?

Accepted Answer

8

Question 7

When constructing a grouped frequency distribution, which of the following is a key requirement for the intervals?

Accepted Answer

Intervals must be equal in width.

Question 8

A stem-and-leaf display is most useful for which of the following purposes?

Accepted Answer

Displaying all individual data points while also showing the distribution shape.

Question 9

Suppose you have the following data: 22, 22, 24, 29, 30, 33, 33, 40, 60. In a stem-and-leaf plot, what would be the 'stem' for the value 33?

Accepted Answer

3

Question 10

Why is it important to visualize data, even when summary statistics (like mean and standard deviation) are available?

Accepted Answer

Visualization can reveal patterns, outliers, or relationships that summary statistics may obscure.

Question 11

If a frequency distribution for exam scores uses intervals of width 5 (e.g., 0-4, 5-9, 10-14), and the data range from 13 to 29, what is the lowest interval that should be included?

Accepted Answer

10-14

Question 12

Given a dataset with the following relative frequencies: 0.10, 0.30, 0.40, 0.10, 0.10, what is the sum of all relative frequencies?

Accepted Answer

$1.00$

Question 13

A bar graph is most appropriate for which type of variable?

Accepted Answer

Nominal or ordinal variables

Question 14

Which of the following is a potential drawback of using only summary statistics to describe a dataset?

Accepted Answer

Summary statistics can oversimplify and hide important features such as outliers or multimodal distributions.

Question 15

If the frequency of age 19 is 4, age 20 is 3, age 21 is 1, and age 18 is 1 in a sample of $N = 10$, what is the percentage of participants aged 19?

Accepted Answer

$40\%$

Question 16

In a grouped frequency distribution, if the interval width is 5 and the lowest value is 13, what is the correct lower boundary for the first interval?

Accepted Answer

10

Question 17

Which of the following best describes a cumulative relative frequency?

Accepted Answer

The sum of the relative frequencies for all values up to and including a given value.

Question 18

A psychologist wants to display the distribution of reaction times (a continuous variable) for two groups. Which type of graph is most appropriate?

Accepted Answer

Histogram or frequency polygon

Question 19

If a dataset is summarized as $M = 3.23$, $SD = 1.07$, what does $SD$ represent?

Accepted Answer

The standard deviation, a measure of the spread or variability of the data.

Question 20

Which of the following is NOT a step in constructing a frequency distribution?

Accepted Answer

Calculating the correlation coefficient $r$.

Summarizing Data: Frequency Distributions, Visualization, and Data Tables in Psychology

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