SOLUTION: It is reported that the average daily viewing of television is 8.5 hrs per household with a standard dev of 2.5 hours. assuming that the number of hours viewing tv is normally dist

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Question 437883: It is reported that the average daily viewing of television is 8.5 hrs per household with a standard dev of 2.5 hours. assuming that the number of hours viewing tv is normally distributed, find.
the prob that a randomly selected household views tv between 7.5 and 9 hours
how many house of viewing a household should have in order to be in the top 2% of all tv viewing households.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
It is reported that the average daily viewing of television is 8.5 hrs per household with a standard dev of 2.5 hours. assuming that the number of hours viewing tv is normally distributed,
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find the prob that a randomly selected household views tv between 7.5 and 9 hours
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z(7.5) = (7.5-8.5)/2.5 = -1/2.5
z(9)= (9-8.5)/2.5 = 1/2.5
P(7.5< x < 9) = P(-1/2.5 < z < 1/2.5) = 0.6492
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how many hours of TV viewing a household should have in order to be in the top 2% of all tv viewing households.
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Find the z-value that has a left tail of 98%.
invNorm(0.98) = 2.0537
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find the corresponding x-value:
x = zs + u
x = 2.0637*2.5 + 8.5 = 13.63..
Cheers,
Stan H.