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According to bottled water trends, the u .s.
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Per capita consumption of bottled water in 2013 was 31 .8 gallons.
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Assume that the per capita consumption of bottled water is approximately normally distributed, with a mean of 31 .8 gallons and a standard deviation of 10 gallons.
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Part a, what is the probability that someone in the united states consumed more than 32 gallons of bottled water? so do 1 minus the probability that z is less than 32 minus 31 .8? divided by 10, which is 1 minus the probability that z is less than .02, which corresponds to .4920 for a probability.
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Part b, what is the probability someone in the united states consumed between 10 and 20 gallons? so we'll do the probability of 10 minus 31 .8 divided by 10.
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It's less than z, which is less than 20 minus 38, oh, excuse me, 31 .8 divided by 10.
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That's going to put z in between negative 2 .2.
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And negative 1 .18.
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So we'll be subtracting 0 .1190 and 0 .146 for a total of 0 .1044.
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For part c, what's the probability that someone in the united states consumed less than 10 gallons? so we've already calculated 10 gallons, so it's probability that z is less than negative 2 .18, which is 0 .146.
01:47
And then for d, 99 % of the people in the united states consume, less than how many gallons of water.
01:55
So first we have to take the 99th percentile and convert it to a z score...