Question

a, What is a key difference between an EXPERIMENTAL STUDY and a CORRELATIONAL STUDY?

Group of answer choices

In an experiment, the researcher actively manipulates the independent variable and measures the dependent variable to determine if the independent variable had an effect on the dependent variable. In a correlational study, the researcher measures both variables to determine if there is a relationship between the two variables.

Experimental research studies summarize and organize sample data whereas correlational studies make decisions about population scores and relationships based on sample data.

In a correlational study, the researcher actively manipulates the independent variable and measures the dependent variable to determine if the independent variable had an effect on the dependent variable. In an experimental study, the researcher measures both variables to determine if there is a relationship between the two variables.

b. Whereas a bar chart is most appropriate to graph nominal data, the histogram is most appropriate to graph ____________ data; and if we detect in the histogram a positive skew, we would know that the _____________ is greater than the _______________.

Group of answer choices

ratio; mean; median

ratio and ordinal; mode; mean and median

interval and ordinal and nominal; median; mean

ordinal; median; mean

c. This is the saddest story ever told: Being on the verge of accepting Ale's marriage proposal, Pam just needed to be sure that she would marry the "statistics buff" he was always boasting to be. So, one day Pam set out to test the veracity of his claim, and that would ultimately determine whether they would tie the knot forever:

Pam began, "Say I divide the squared sum of x by N; I then take the result and subtract it from the sum of x squared. This result gets divided N. What is the name of this statistical computation?" Without any hesitation, Ale arrogantly grunted and replied: "That's an easy one; it's the sample standard deviation, a measure of variability!" Tearfully, Pam ended their relationship on the spot. What was wrong with Ale's answer?

Group of answer choices

the standard deviation is a measure of central tendency

the answer should have been the sample range

the correct answer should have been the sample variance

d. Professor Nicole Barbari found in her research the Pearson r correlation coefficient to be rout =  -.749. What two things can she deduce from the coefficient automatically?

Group of answer choices

negative direction and strong relationship

weak relationship and positive direction

she will reject Ho

the more x, the more y and weak relationship

e. What statistical procedure will solve this problem? An elementary teacher predicts students in a randomly selected sample will have more nightmares after watching Jaws than Pretty Woman. The participants are shown Jaws first. The next day, the same participants are shown Pretty Woman.

Group of answer choices

dependent t

one sample t

one sample z

independent t

Answer 1

a, What is a key difference between an EXPERIMENTAL STUDY and a CORRELATIONAL STUDY?

Answer : In an experiment, the researcher actively manipulates the independent variable and measures the dependent variable to determine if the independent variable had an effect on the dependent variable. In a correlational study, the researcher measures both variables to determine if there is a relationship between the two variable.

b. Whereas a bar chart is most appropriate to graph nominal data, the histogram is most appropriate to graph ____________ data; and if we detect in the histogram a positive skew, we would know that the _____________ is greater than the _______________.

Answee : ratio; mean; median

c. This is the saddest story ever told: Being on the verge of accepting Ale's marriage proposal, Pam just needed to be sure that she would marry the "statistics buff" he was always boasting to be. So, one day Pam set out to test the veracity of his claim, and that would ultimately determine whether they would tie the knot forever:

Pam began, "Say I divide the squared sum of x by N; I then take the result and subtract it from the sum of x squared. This result gets divided N. What is the name of this statistical computation?" Without any hesitation, Ale arrogantly grunted and replied: "That's an easy one; it's the sample standard deviation, a measure of variability!" Tearfully, Pam ended their relationship on the spot. What was wrong with Ale's answer?

Answer : the correct answer should have been the sample variance

d. Professor Nicole Barbari found in her research the Pearson r correlation coefficient to be rout =  -.749. What two things can she deduce from the coefficient automatically?

Answer : negative direction and strong relationship

e. What statistical procedure will solve this problem? An elementary teacher predicts students in a randomly selected sample will have more nightmares after watching Jaws than Pretty Woman. The participants are shown Jaws first. The next day, the same participants are shown Pretty Woman.

Answer : dependent t