Question

a.)Visitors to a farm are polled about how many apples they picked in one hour. This is an example of _______ measurement. Which type of basket they pick is an example of ________ measurement.

b.)For what kind of distribution would you report the median rather than the mean? Why? Include an example. When would you report the mode?

c.)When would you use descriptive vs inferential statistics? Why? Give an example of the type of experiment each would use.

d.)Give a mean and standard deviation that would indicate a majority of children are on their phones between 1.3 and 3.3 hours a day.

e.)What is the interquartile range? When would you use it?

f.)A friend is told that her Z scores were 2.5, 1.0. -.5 for three final exams. Which one shows the worst performance and why? Which one shows the best?

g.)What is the relationships of a critical value to an observed value in a t test and ANOVA? Where do you find them and what do they mean?

h.)Is it possible that you could satisfy both p < .01 and p< .05? Is it possible to only have one or the other exclusively? Explain.

i.)In a T test for two independent samples, the null hypothesis is that the difference between population means is ______________?

j.)What are the hypothesis tests that make up an ANOVA? What is the purpose of the test? What is an example of a question that you would ask with an ANOVA? What is an example of a situation that would require you to use t tests and an ANOVA? What are those t tests called? When would you use an ANOVA but not use t tests?

k.)Let’s say that we are testing the effect of distance on self-disclosure. The distances are 2, 4, or 6 ft. The interviewer measures the number of personal, revealing statements made by the subject. Complete the ANOVA and the summary Table below. Is the F value significant at the .05 level? Is it significant at the .01 level? What are the critical and observed values? What do they mean?

l.)Compute the Pearson Correlation Coefficient ( r ) in the problem below. Is it significant? What does that mean? What are the critical values and observed values? What do those mean? What is the relationship – positive or negative? What does that mean?

m.)What is an example of a positive relationship and negative relationship that you have seen in the news? What is an examples of an illusory correlation? Why do people say ‘correlation is not causation’?

Answer 1

a.

Visitors to a farm are polled about how many apples they picked in one hour. This is an example of ratio measurement. Which type of basket they pick is an example of nominal measurement.

b.

For skewed distribution we use median rather than mean.

Ex. Income of people in the town. This is positively skewed distribution. Hence median o income is the best measure of central tendency.

Mode : Generally mode is best measure of central tendency for dealing with nominal data.

Ex. Favorite ice-cream flavor.

f.

Higher z score means higher performance.

Here the student with z score -.5 , has worst performance, and the student with z score 2.5 has best performance.

i.

In a T test for two independent samples, the null hypothesis is that the difference between population means is zero.