PLEASE HELP WILL GIVE BRAINLIEST! (03.01 LC)
For a certain experiment, the available experimental units are eight people: four females (f) and four males (m). Use (1f, 2f, 3f, 4f) to denote the females and (1m, 2m, 3m, 4m) to denote the males. There are to be four treatment groups: A, B, C, and D. If a randomized block design is used, with the experimental units blocked by gender, which assignment of treatments is correct?

Select one:
a. A: (1f, 3f), B: (2f, 2m), C: (4f, 1m), D: (4m, 3m)
b. A: (2m, 1m), B: (1f, 2f), C: (3m, 3f), D: (4f, 4m)
c. A: (3m, 1m), B: (2f, 4f), C: (3f, 1f), D: (4m, 2m)
d. A: (1f, 3m), B: (2f, 2m), C: (3f, 1m), D: (4f, 4m)
e. A: (1f, 2f), B: (1m, 2m), C: (3f, 3m), D: (4f, 4m)

(03.05 MC)

A researcher wants to know how licensed drivers in the United States feel about establishing a law that requires individuals to take and pass another driving test at the age of 65 to determine whether they may retain their license. The researcher mails a survey to a random sample of 10,000 drivers out of all licensed drivers in the US. A total of 6,457 out of the 10,000 respond and 46% say they favor the test. Which of the following is true based on this information?

Select one:
a. There is sufficient evidence that the percentage of all licensed drivers who say they favor the test is close to 46% because random sampling was used.
b. There is evidence of nonresponse bias in the survey results.
c. The results of this survey are invalid because the survey was mailed and not a face-to-face interview.
d. There is sufficient evidence that the percentage of all licensed drivers who say they favor the test is close to 46% because more than half of those who were mailed the survey responded.
e. There is strong evidence of convenience response bias in the survey results.

(03.05 LC)

A researcher wants to conduct a study to see if cell phones cause headaches. The researcher finds 30 individuals who use cell phones regularly and 30 that do not. Each of the 60 individuals are given a questionnaire designed to determine headache frequency. If the 60 individuals did not know they were participating in the study, which statement about the study is correct?

Select one:
a. It is an experiment where cell phone habits is a blocking variable.
b. It is an observational study.
c. It is a matched-pairs design.
d. It is a randomized experiment.
e. It is a double-blind study.