PSY 216: Exam 2_2024

PSY 216: Exam 2 Review

Open Ended

Describe central tendency and the type of statistic it is.

Multiple Choice

The mean is the mid-point in a data set when the data has been arranged in order.

• True

• False

Multiple Choice

You have a set of data that captures the temperatures in the summer, you want to describe the data using a measure of central tendency. Looking at the data it does not appear to be skewed or have any undetermined values. What measure of central tendency should you use?

• Mean

• Weighted Mean

• Mode

• Median

Multiple Select

How many modes can a set of data have? (select all the apply)

• One

• None

• More Than One

• It can only have one

Multiple Choice

If a data set has a mean of 7 and a n = 23, what happens to the mean if the value 12 is added to the data set?

• 6.5

• 7.6

• 6.9

• 7.2

Multiple Choice

A researcher is conducting an experiment to evaluate the effectiveness of three different types of cognitive training programs on improving attention span. Each program was tested on a different number of participants, and the average improvement scores were recorded. What measure of central tendency should you use?

• Mean

• Weighted Mean

• Mode

• Median

Multiple Select

Median and mode can be used to describe data that uses a _____ scale.

• Nominal

• Ordinal

• Interval

• Ratio

Open Ended

What is variability in a dataset, and why is it important for understanding the data?

Multiple Choice

Which is not a measure of variability?

• Standard Deviation

• Interquartile Range

• Range

• Variance

• None of the above

Multiple Choice

A data set has a mean of 7.5, median of 8.5, and mode of 9 how would you describe the data set?

• Negative Skew

• Positive Skew

• Unimodal

• Bimodal

Multiple Choice

Find the range for the below sample and describe the range.

25, 15, 13, 18, 21, 12, 11, 7, 3, 20

• 23; moderate range

• 22; high range

• 23; high range

• 18; low range

Multiple Choice

When calculating Sum of Squares (SS) we must square the deviation scores because the numbers are too small and we need to make them bigger so they are easier to add.

• True

• False

Multiple Choice

What measure of variability should be used when data is skewed or has outliers?

• Interquartile Range

• Variance

• Range

• Standard Deviation

Multiple Choice

The mean is a good representation of the distribution when variability is:

• Low

• Irregular

• High

• Extreme

Open Ended

Describe degrees of freedom and when to use it (include the formula).

Multiple Choice

A deviation score gives us a numerical value that tells us how far away the score is from the mean and the sign (±) tells us which direction the score is from the mean.

• True

• Fasle

Open Ended

Find the Standard Deviation for the below sample of data. Be sure to show your work and use the correct symbols.

11, 15, 16, 3, 14, 12

What does this tell us?

Open Ended

Create a box-and-whisker plot using this data: 10, 20, 30, 30, 40, 65, 72, 80, 80, 83, 85 and describe the data set.

Open Ended

What information does a z-score provide about a data point in a data set?

Multiple Choice

What does a +1.6 z-score tell us about the original score from a population?

• The original score from the sample is $$1.6s$$ below the mean

• The original score from the population is $$.8s$$ above the mean

• The original score from the population is $$1.6\sigma$$ above the mean

• The original score from the sample is $$1.2\sigma$$ below the mean

Multiple Choice

You take a test and find that its mean is 82, with a standard deviation of 1.2. Your professor tells you that your z-score is -0.5. What is your original score?

• 79.6

• 80.9

• 83

• 81.4

Multiple Select

What happens to the shape, mean, and standard deviation of a distribution after it
is transformed into z-scores (select all that apply)?

• Nothing

• Mean is transformed to 0

• Standard Deviation is transformed to 1

• The shape of the distribution remains the same

Multiple Choice

A researcher wants to transform scores from a distribution with μ= 70 and σ = 12 to a
distribution with μ = 100 and σ = 5 (round to two decimals where appropriate). What is the
new value of X = 98 when it is transformed to the new distribution?

• 2.33

• -0.4

• 65.2

• 111.65

Multiple Select

Select all that indicate the data is from a population

• σ

• s

• σ²

• μ

• x̄

Multiple Select

Select all that indicate the data is from a sample

• s

• σ

• s²

• μ

• x̄