Stats Test #1

What is the value of the median for the following set of scores? Scores: 1, 3, 4, 6, 8, 12, 13, 23, 25, 26

10

A sample of n = 6 scores has a standard deviation of s = 3. What is the value of SS, the sum of the squared deviations for this sample?

18

Under what circumstances should the chi-square statistic not be used?

If fe < 5 for any cell

A population with a mean of m = 6 has SX = 54. How many scores are in the population?

N=9

What conclusion is appropriate if a chi-square test produces a chi-square statistic near zero?

There is a good fit between the sample data and the null hypothesis.

In a frequency distribution graph, frequencies are presented on the , and the scores (categories) are listed on the .

Y axis, X axis

The normal distribution is an example of

a smooth curve showing data from a population.

What kind of frequency distribution graph shows the frequencies as bars, with no space between adjacent bars?

histogram

A population of scores has a mean of µ = 26, a median of 23, and a mode of 22. What is the most likely shape for the population distribution?

positively skewed

A chi-square test for independence is used to evaluate the relationship between two variables. If both variables are classified into 2 categories, then what is the df value for the chi-square statistic?

1

What is the shape of the distribution for the following set of data? Scores: 1, 2, 3, 3, 4, 4, 4 5, 5, 5, 5, 6

Negatively skewed

For the following scores, which of the following actions will increase the range?Scores: 3, 7, 10, 15

Subtract 3 points from the score X = 3

Students in an introductory art class are classified as art majors and non-art majors. What scale of measurement is being used to classify the students?

nominal

Which of the following symbols identifies the sample variance?

s^2

What is the mode for the population of scores shown in the frequency distribution table? Xf5142332412

2

What is the value of SS for the following set of scores? Scores: 8, 3, 1.

26

What is the value of SS (sum of squared deviations) for the following sample? Sample: 1, 1, 1, 7

27

After 5 points are subtracted from every score, the sample mean is found to be M = 24. What was the mean for the original sample?

29

A sample has a mean of M = 90. If each score in the sample is multiplied by 5, then what is the mean for the new distribution?

450

A population of n = 8 scores has SX = 40. What is the population mean?

5

A sample of n = 8 scores has SS = 50. If these same scores were a population, then the SS value for the population would be _____.

50

What is the value of (SX)2 for the scores 1, 5, 2?

64

After every score in a sample is multiplied by 3, the mean is calculated and found to be M = 21. What was the mean for the original scores?

7

A set of scores ranges from a high of X = 96 to a low of X = 11. If these scores were placed in a grouped frequency distribution table, what is the best value for the interval width?

9 points

One sample with n = 4 scores has a mean of M = 12, and a second sample with n = 6 scores has a mean of M = 8. If the two samples are combined, what is the mean for the combined set of scores?

9.6

A biologist records the number of trout, bass, perch, and other types of fish caught in a local lake during a 2-week period. If the results are organized in a frequency distribution table, what values would be listed in the first column?

Different types of fish

One sample is selected to represent scores in treatment 1 and a second sample is used to represent scores in treatment 2. Which set of sample statistics would present the clearest picture of a real difference between the two treatments?

M1 = 36, M2 = 40, and both variances = 6

Which of the following statements cannot be true for a distribution of scores?

No one has a score exactly equal to the mode.

What are the values for SS and variance for the following sample of n = 4 scores? Sample: 1, 1, 0, 4

SS = 9 and variance = 3

A researcher conducts an experiment to determine whether moderate doses of St. Johns Wort have any effect of memory for college students. For this study, what is the independent variable?

The amount of St. Johns Wort given to each participant

Which of the following is a consequence of increasing variability?

The distance from one score to another tends to increase, and a single score tends to provide a less accurate representation of the entire distribution.

How does the difference between fe and fo influence the outcome of a chi-square test?

The larger the difference, the larger the value of chi-square and the greater the likelihood of rejecting the null hypothesis.

Which of the following is a basic assumption for a chi-square hypothesis test?

The observations must be independent.

A chi-square test for goodness of fit is used to examine the distribution of individuals across four categories, and a chi-square test for independence is used to examine the distribution of individuals across the six categories in a 2´3 matrix of categories. Which test has the larger value for df?

The test for goodness of fit

For the following frequency distribution, what is SX? X f 30-34 1 25-29 1 20-24 3 15-19 2 10-14 1

cannot be determined

What kind of variable requires the use of real limits?

continuous

Organizing a set of scores in a table is an example of using _______.

descriptive stats

If a set of scores is displayed in a frequency distribution polygon, what scale of measurement was used to measure the scores?

interval or ratio

The participants in a research study are classified as high, medium, or low in self-esteem. What measurement scale is being used to classify self-esteem?

ordinal

A set of 10 scores has SS = 90. If the scores are a sample, the sample variance is ____, and if the scores are a population, the population variance is ____.

s2 = 10; s2 = 9

A researcher is interested in the eating behavior of rats and selects a group of 25 rats to be tested in a research study. The group of 25 rats is an example of a ______.

sample

If sample variance is computed by dividing SS by n, then the average value of the sample variances from all the possible random samples will be _______ the population variance.

smaller than