Question 1

The formula for calculating the difference between two percentages calculates a z value.

Accepted Answer

The formula for calculating the difference between two percentages calculates a z value, which is a measure of the standard deviation.

Question 2

The findings of a research study presented in the textbook comparing purchasing impulses of French and Swedish supermarket shoppers reveal that marketers who seek to stimulate impulse shopping in supermarkets must vary their strategies according to the customs in each country in which they are operating.

Accepted Answer

The research study presented in the textbook found that the strategies to stimulate impulse shopping in supermarkets must be varied according to customs in each country. Therefore, the statement is true.

Question 3

When testing the difference between two percentages from two independent samples,a z value larger than 1.96 indicates the difference is NOT significantly different.

Accepted Answer

A z value larger than 1.96 indicates that the difference between two percentages is statistically significant at the 5% level, meaning that we can reject the null hypothesis that the two percentages are equal. If the z value is smaller than 1.96, we fail to reject the null hypothesis and cannot conclude that the two percentages are different.

Question 4

When testing for differences,a manager must first determine if the differences are meaningful and then act on the differences.Only then should he or she decide if the differences are significantly different.

Accepted Answer

The manager should first determine if the differences are statistically significant before considering if they are meaningful and deciding on actions.

Question 5

Research determines a significant difference between cold remedy preferences depending on symptoms to be relieved.When the marketing manager markets several different remedies,each designed to reduce a different symptom,we can say the differences found in the research are actionable.

Accepted Answer

Since the research has determined a significant difference between cold remedy preferences depending on symptoms to be relieved, the marketing manager can use this information to tailor their marketing strategy accordingly by highlighting the specific benefits of each remedy based on the symptoms it targets. Therefore, the differences found in the research are actionable.

Question 6

As long as different,independent samples are being tested,it is appropriate to run the paired samples test for the differences between two means on one sample's mean height (measured in feet/inches),versus another sample's mean weight (measured in pounds/ounces).

Accepted Answer

The paired samples test is only appropriate when two sets of data are being compared within the same sample, such as before and after measurements of the same individuals. It is not appropriate for comparing the means of two independent samples, such as height and weight. A t-test or a two-sample test would be more appropriate in this case.

Question 7

A group comparison table is often used to summarize significant differences when reporting group differences to clients.

Accepted Answer

A group comparison table is a common way to summarize and present significant differences between groups, making it easier for clients to understand the results of the analysis.

Question 8

If you want to determine the mean score on a research question measuring whether likelihood to purchase a new product differs between respondents in two separate income groups,you would use the independent samples t test.

Accepted Answer

The independent samples t test is appropriate for comparing the means of two groups, such as the mean likelihood to purchase a new product between two different income groups.

Question 9

In the independent samples t test,Levene's test determines whether the variances between the two samples are approximately equal.

Accepted Answer

Levene's test is used to test the assumption of equal variances in the independent samples t-test. If the p-value obtained from Levene's test is less than the significance level (alpha) selected, we reject the null hypothesis of equal variances and use the adjusted degrees of freedom for the t-test.

Question 10

In the test to determine significance difference between two means generated by independent samples,there is no provision for testing a directional hypothesis such as "males drink more soft drinks per week than females."

Accepted Answer

The test for significance difference between two means generated by independent samples does provide for testing a directional hypothesis. This is done through a one-tailed test, where the researcher specifies the direction of the difference (e.g. males have higher mean than females) and only looks at the corresponding tail of the distribution.

Question 11

When testing the difference between two percentages from two independent samples,SPSS will not make this calculation.You must do it by hand.

Accepted Answer

SPSS does not have a built-in function to calculate the difference between two percentages from two independent samples. This calculation must be done manually using the formula:(p1 - p2) / sqrt(p1 * (1 - p1) / n1 + p2 * (1 - p2) / n2)where p1 and p2 are the two percentages, and n1 and n2 are the sample sizes.

Question 12

Unfortunately,SPSS cannot run the paired samples t test.

Accepted Answer

SPSS can run paired samples t tests.

Question 13

SPSS will report analysis of differences tests in terms of t tests.

Accepted Answer

SPSS can perform various types of test including t-tests, ANOVA, MANOVA, etc. However, when running tests for differences between groups, such as comparing means or proportions, t-tests are a common method used and the results are reported in terms of t-tests.

Question 14

Statisticians have found that data do not meet the assumption of being normally distributed with sample sizes of 300 or more.

Accepted Answer

With large sample sizes (typically 30 or more), the Central Limit Theorem suggests that the sampling distribution of the sample mean will be approximately normally distributed, regardless of the shape of the population distribution.

Question 15

Different tests are required to test the differences between the means of two samples depending upon whether or not the two samples are independent or are paired.

Accepted Answer

This is true. If the two samples are independent, a two-sample t-test or a Welch's t-test may be used to test the difference between their means. If the two samples are paired, a paired t-test or a Wilcoxon signed-rank test may be used.

Question 16

When we test for the differences between two groups,the null hypothesis is that the difference in the two groups' population parameters is more than 30.

Accepted Answer

The question does not provide enough information about the specific hypothesis being tested or the type of test being used. The null hypothesis can vary depending on the situation and the test being conducted. Additionally, a difference of 30 is not typically used as a threshold for determining statistical significance.

Question 17

ANOVA is used to determine if there is any correlation among three or more paired groups or samples.

Accepted Answer

ANOVA is used to determine if there are statistically significant differences in the means of three or more independent groups, not to find correlations.

Question 18

The statistical significance "flag" in SPSS is called the p value by statisticians and is denoted with "significance" or "probability" or their abbreviations.

Accepted Answer

The statement is correct. The p value represents the probability of obtaining the observed differences (or more extreme) by chance alone, and it is usually denoted with "significance" or "probability" or their abbreviations (e.g. p or alpha). SPSS includes this information in the output of statistical tests.

Question 19

While researchers are expected to report research results accurately and honestly,it is not necessary to include any results that may seem contradictory or unfavorable.

Accepted Answer

Including contradictory or unfavorable results is important for the integrity of the research process and for the overall advancement of knowledge in the field. It allows for transparency and helps to prevent biased or incomplete conclusions.

Question 20

The t test is the statistical inference test to be used with small sample sizes less than or equal to 30.

Accepted Answer

The t test is designed for small sample sizes and is appropriate when sample size is less than or equal to 30.

Quiz 13: Implementing Basic Differences Tests