A certain brand of toothpaste, Colcrest, is advertised as being preferred by 7 out of 10...

A certain brand of toothpaste, Colcrest, is advertised as being preferred by 7 out of 10 dentists. Assume that this is true. A simple random sample of 6 dentists is taken.

a. Calculate the probability that 4 or fewer of the 6 dentists prefer Colcrest.

b. What is the average (or mean) number of dentists for this sample of size 6 who prefer Colcrest? What is the standard deviation?

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Expert Solution

Answer:

Given that:

A certain brand of toothpaste, Colcrest, is advertised as being preferred by 7 out of 10 dentists. Assume that this is true. A simple random sample of 6 dentists is taken.

sample size(n) =6

a) Calculate the probability that 4 or fewer of the 6 dentists prefer Colcrest.

b) What is the average (or mean) number of dentists for this sample of size 6 who prefer Colcrest? What is the standard deviation?

The average = np = 6*0.7 = 4.2

Standard deviation =

orchestra answered 1 year ago

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