Question 1

SPSS will always determine the correct significance level whether it is a t or a z,you do not need to worry about which statistic to use.

Accepted Answer

SPSS automatically calculates the correct significance level, whether the test is a t or z test.

Question 2

With a differences test,the null hypothesis states there are significant differences between the percentages(or means)being compared.

Accepted Answer

The null hypothesis for a differences test (also known as a two-sample hypothesis test) states that there are no significant differences between the percentages (or means) being compared. The alternative hypothesis is that there are significant differences between them.

Question 3

Market segmentation requires that standard or innovative market segmentation bases are used,and that these bases uniquely identify the various groups so they can be analyzed and put in the marketer's targeting mechanisms.

Accepted Answer

Market segmentation requires the use of standard or innovative bases to identify groups for targeting, so they can be analyzed and effectively targeted by the marketer.

Question 4

It is a simple matter to apply formulas to percentages to determine the significance of their differences,for all that is needed is the sample size of each group.

Accepted Answer

This statement is incorrect. The sample size alone is not sufficient to determine the significance of differences between percentages. Other factors such as the size of the effect, variance, and statistical tests should also be considered.

Question 5

Statistical tests are used when a researcher wants to compare the medians of two different groups or samples.

Accepted Answer

Statistical tests are used when a researcher wants to compare the means of two different groups or samples, not medians.

Question 6

Virtually every statistical test or procedure involves the computation of some critical statistic,and that statistic is used to determine the statistical significance of the findings.

Accepted Answer

Statistical tests and procedures typically use a critical statistic to determine the statistical significance of the findings. This critical statistic is compared to a predetermined threshold, known as the alpha level, to determine whether the results are statistically significant or not.

Question 7

A researcher must fall back on statistical significance to determine whether the difference that is found between the two sample statistics is a true population difference.

Accepted Answer

Statistical significance helps to determine whether the difference observed between two sample statistics is likely to be a true population difference or just due to chance.

Question 8

The procedure for testing significance of difference between two means from two different groups is identical to that used in testing two percentages.However,the equations differ because a scale variable is involved.

Accepted Answer

The statement is true. While the procedure for testing significance of difference between two means from two different groups may be similar to that used in testing two percentages, the equations for calculating the significance level differ as a scale variable is involved in the former case.

Question 9

SPSS does not perform tests of the significance of the difference between the percentages of two groups,but the researcher can use SPSS to generate the relevant information and perform a hand calculation.

Accepted Answer

SPSS can generate the percentages and data needed to perform a hand calculation for the significance of the difference between two groups, but it does not directly perform this test.

Question 10

The computation of the z value makes the assumption that the raw data for most statistics under scrutiny have normal or bell-shaped distributions.

Accepted Answer

The computation of the z value assumes that the data is normally distributed.

Question 11

ANOVA is used when comparing the means of three or more groups.

Accepted Answer

ANOVA (Analysis of Variance) is specifically designed for analyzing the variation between means of three or more groups.

Question 12

Once the number of standard errors is known,knowledge of the area under the normal curve will yield an assessment of the probability of support for the null hypothesis.

Accepted Answer

This statement is true. When the number of standard errors is known, the Z-score can be computed, and by looking at the area under the normal curve, we can assess the probability of support for the null hypothesis.

Question 13

Statisticians have been able to show that the normal bell curve property also occurs when the sample size is 30 observations or fewer.

Accepted Answer

The normal bell curve, or the central limit theorem, typically applies when sample sizes are large (usually n > 30). For smaller sample sizes, the distribution of the sample mean may not approximate a normal distribution unless the population distribution is normal.

Question 14

With SPSS,the analyses of differences are referred to as Z tests.

Accepted Answer

The analyses of differences in SPSS are not specifically referred to as Z tests. SPSS offers a wide range of statistical tests and techniques for analyzing different types of data, and the appropriate test depends on the research question, data type, and assumptions of the analysis. Z tests are just one type of statistical test that can be used in SPSS for specific hypotheses and data types.

Question 15

If the null hypothesis is true,when you subtract one group mean from the other,the result should be zero or a negative number.

Accepted Answer

The result can be zero, a negative number, or a positive number, depending on the direction of the difference between the two group means; the null hypothesis simply posits no true difference in the population means, not the direction or magnitude of any sample mean differences observed.

Question 16

The t test is defined as the statistical inference test to be used with large samples sizes(n ? 30).

Accepted Answer

The t test can be used with both small and large sample sizes, but with small sample sizes (n < 30) it is less accurate and can lead to unreliable results.

Question 17

With a differences test,the researcher tests the null hypothesis that no differences exist between the two group means(or percentages).

Accepted Answer

A differences test, also known as a t-test or z-test, is used to determine if there is a statistically significant difference between the means or percentages of two groups. The null hypothesis is that there are no differences between the two groups, and the alternative hypothesis is that there is a significant difference. The researcher uses the results of the test to either reject or fail to reject the null hypothesis.

Question 18

Independent samples are treated as representing two potentially different populations.

Accepted Answer

Independent samples are taken from two different groups or populations and are not related to each other. Therefore, they are considered to represent potentially different populations.

Question 19

The sample size of 30 or greater requires the use of a z test.

Accepted Answer

This statement is true. When the sample size is 30 or greater, the sample mean follows a normal distribution by the Central Limit Theorem. Therefore, a z-test can be used to test hypotheses about the population mean.

Question 20

The second step in determining differences between percentages with two groups,requires that this difference be translated into a number of standard errors away from the hypothesized value of zero.

Accepted Answer

This is true. In order to determine the statistical significance of the difference between two percentages, we need to calculate the standard error and use it to calculate a z-score, which tells us how many standard errors the difference is from the expected value of zero.

Quiz 12: Using Basic Descriptive Analysis, Performing Population Estimates, and Testing Hypotheses