A Brief Quiz on chapter 12
Choose the correct answer for each question. To print your answer, use the browser "Print" command.

1Descriptive statistics are tools that help researchers draw
conclusions about the probable populations from which
samples did or did not belong.

2The mean is the middle score in a distribution.

3The variance is the difference between the highest and lowest scores.

4In essence, the standard deviation is a measure that shows how far scores deviate from the mean on the average.

5Skewness refers to the location of the "hump" of data in a distribution.

6Look at these two symbolsstd1.gif
The first symbol represents the variance of the sample whereas the second symbol represents the variance of the population.

7The standard normal curve is a data distribution that tells the expected value that would be obtained by sampling at random.

8A correlation indicates the presence of a causal relationship.

9Z scores transform actual sample data into units of a distribution with a mean of 0 and a standard deviation of 1.

10A correlation coefficient with a negative sign in front of it indicates a lower correlation than one with a positive sign.

11A Pearson product moment correlation is used when each variable is on the ordinal scale.