n= z(2)pq/e(2)

Key Variable	Variability	Acceptable Error	Confidence Level
Market share of Crest toothpaste last year	23% share	4%	95%
Percentage of people who brush their teeth 2x per day	Unknown	5%	99%
Likelihood to switch toothpaste brands the next time they purchase toothpaste (scale of 1- 7 where 1 = extremely likely and 7 = not at all likely)	Unknown	12 a point on the scale	95%

1)Which of the following is the correct sample size for a study to measure Crests market share? a. 425 b. 600 c. 737 d. 1040

1. 2)Which of the following is the correct sample size to learn the percentage of people who brush their teeth 2x per day? a. 384 b. 425 c. 666 d. 1040
2. 3)Which of the following is the correct sample size to understand how likely Crest buyers are to switch brands the next time they buy toothpaste? a. 21 b. 36 c. 84 d. 145
3. 4)Lets assume Crests annual survey is among a random sample of US residents between the ages of 18 to 75 who registered on the Crest website as a product user. 5)Which sampling method is Crest using to conduct this survey? a. Probabilistic Sampling b. Non-Probabilistic Sampling c. A mix of both Probabilistic Sampling and Non-Probabilistic Sampling d. None of the above