A nationwide census is conducted and it is found that the mean number of hours of television watched per year by Americans is 350 with a standard deviation of 220. Furthermore, the data appears to be normally distributed! Using this information, determine the probability that a group of 4 Americans watch MORE THAN 400 hours of television per year. SHOW ALL WORK.

Probability that a group of 4 Americans watch more than 400 hours of television per year is 0.3264.

Step-by-step explanation:

We are given that a nationwide census is conducted and it is found that the mean number of hours of television watched per year by Americans is 350 with a standard deviation of 220.

A group of 4 Americans is selected.

Let = sample mean number of hours of television watched per year

The z score probability distribution for sample mean  is given by;

                             Z  =    ~ N(0,1)

where, = population mean = 350

            = standard deviation = 220

            n = sample of Americans = 4

Now, the probability that a group of 4 Americans watch more than 400 hours of television per year is given by = P( > 400 hours)

     P( > 400) = P( > ) = P(Z > 0.45) = 1 - P(Z 0.45)

                                                        = 1 - 0.6736 = 0.3264

The above probability is calculated by looking at the value of x = 0.45 in the z table which has an area of 0.6736.

Hence, the probability that a group of 4 Americans watch more than 400 hours of television per year is 0.3264.

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step-by-step explanation: