11. (a) Consider a study designed to investigate the following claim. A toothpaste with an active ingredient is effective in reducing
plaque buildup on teeth.
The following design is proposed for the study.
Obtain 170 volunteers from the population of people with plaque buildup on
their teeth. Randomly assign 90 of the volunteers to use the toothpaste with
an active ingredient each day. Assign the remaining 80 volunteers to use a
placebo each day. Observe the number of people who experienced a reduction
of plaque buildup in each group after six months.
Is this an observational study or an experiment? Explain.

Which of the following are accepted without proof in a logical system? check all that apply.

Barbara has a good credit history and is able to purchase a car with a low-interest car loan. she co-signs a car loan for her friend jen, who has poor credit history. then, jen defaults on the loan. who will be held legally responsible by the finance company and why? select the best answer from the choices provided. a. barbara will be held legally responsible because she has a good credit history. b. jen will be held legally responsible because she drives the car. c. barbara will be held legally responsible because she is the co-signer. d. jen will be held legally responsible because she has a poor credit history. the answer is a

Find the distance between the pair of points a(-1,8) and b(-8,4)