4.20. According to a report released by the National Center for Health Statistics, 51% of U. S. households has only cell phones (no land line). According to the FCC, nearly 70% of the U. S. households have high-speed Internet. Suppose of the U. S. households having only cell phones, 80% have high-speed Internet. A U. S household is randomly selected. a. What is the probability that the household has only cell phones and has high-speed Internet

The probability that the household has only cell phones and has high-speed Internet is 0.408

Step-by-step explanation:

Let A be the event that represents U.S. households has only cell phones

Let B be the event that represents U.S. households have high-speed Internet.

We are given that 51% of U.S. households has only cell phones

P(A)=0.51

We are given that 70% of the U.S. households have high-speed Internet.

P(B)=0.7

We are given that U.S. households having only cell phones, 80% have high-speed Internet. A U.S household is randomly selected.

P(B|A)=0.8

Hence the probability that the household has only cell phones and has high-speed Internet is 0.408

it costs $20 to interview each person for a survey. find the cost to obtain a +- 3% margin of error.

step-by-step explanation:

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