In a recent survey 35 percent indicated chocolate was their

In a recent survey, 35 percent indicated chocolate was their favorite flavor of ice cream. Suppose we select a sample of eight people and ask them to name their favorite flavor of ice cream.

How many of those in the sample would you expect to name chocolate? (Round your answer to the nearest whole number.)

What is the probability exactly four of those in the sample name chocolate? (Round your answer to 4 decimal places.)

Solution

1) Sample size =8.

Proportion = 35%

No of persons in the sample you  wouldexpect to name chocolate = 8(35%)

= 2.80.

Nearly 3 persons we can expect.

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b) X - no of persons naming the chocolate follows a binomial with n = 8 and p =0.35

Hence P(X=4) = 8C4(0.35)⁴(0.65)⁴⁼0.1875

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c) P(x>=4) = P(X=4)+ P(X=5)+ P(X=6)+ P(X=7)+ P(X=8)

=0.2936