Review Test Research III

When all the values in a distribution are the same, the variance is ___________.

• one

• zero

• maximum

• cannot be determined

Which of the following is CORRECT about the variance?

• The smaller the variance, the more heterogenous are the data values.

• The bigger the variance, the data tends to deviate less from the mean.

• The lesser the variance, the data values tend to deviate more from the mean.

• The bigger the variance, the data values tend to deviate more from the mean.

Which among the following is NOT true about the measures of variation?

• It is also known as measures of spread.

• The lower the variability the lesser the spread of scores.

• The higher the variability the higher the spread of scores.

• It does not tell us that the scores are compressed or spread out.

The average score in the test of section A is 36. Section B also gained the same average scores on the same test. However, section A has a standard deviation of 3.8 while section B has a standard deviation of 1.9. In which section are the scores less dispersed?

• section A

• section B

• no enough information

• could not be determined

A financial analyst sampled the top six companies' book value (in billions of pesos). They are:

7, 15, 18, 22, 25, 33

Approximately, what is the sample mean, as well as the sample standard deviation?

• 20 and 7.2 respectively

• 20 and 8.9 respectively

• 120 and 9.2 respectively

• 120 and 8.9 respectively

Which of the following statements is correct?

• Group A is more varied than Group B because the sample size is larger.

• Group A is less varied than Group B because Group A's standard deviation is bigger.

• Group A is less varied than Group B because its standard deviation per animal is smaller.

• Group A is relatively less varied than Group B because Group A's coefficient of variation is smaller.

Which of the following is a statistical method that measures the strength of the linear relationship between two variables?

• z-value

• scatterplot

• testing hypothesis

• Pearson correlation

In the Pearson r, what does n represent?

• sum of x-values

• sum of square x-values

• number of paired values

• sum of the products of paired values x and y

Which of the following values CANNOT represent a correlation coefficient r ?

• -1

• 0

• 0.35

• 1.05

Which of the following is the range of the correlation coefficient (r)?

• -1 < r < 1

• -1 ≤ r ≤ 1

• 0 ≤ r ≤ 1

• 1 ≤ r ≤ -1