It is estimated that the average person in the US uses 123 gallons of water per day. Some environmentalists believe this figure is too high and conducted a survey of 40 randomly selected Americans. They find a mean of 113.03 gallons and a standard deviation of 25.99 gallons. Calculate the appropriate test statistic to test the hypotheses.

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tanvigupta426 tanvigupta426 · Answer 1 · 2022-07-31T06:38:01+02:00

The value of test statistic is Z = -2.42.

According to the statement

we have given that the person in the US uses 123 gallons of water per day.

And conducted a survey of 40 randomly selected Americans and get a mean value is 113.03 gallons and a standard deviation of 25.99 gallons.

And we have to test the hypotheses with test statistic.

So,

Here we use the the z- test for one population =

Z = (sample mean - Claimed hypothesis mean)/ (standard deviation/(sample size)^1/2.)

Here the sample mean = 113.03

And claimed hypothesis mean = 123

Standard deviation = 25.99

Sample size = 40

Now put the values in the above written formula is

Z = (sample mean - Claimed hypothesis mean)/ (standard deviation/(sample size)^1/2.)

Z = 113.03 - 123 / (25.99/(40)^1/2)

Z = -9.97 / (25.99 / 6.32)

Z = -9.97 / 4.11

Z = -2.42

So, The value of test statistic is Z = -2.42.

Learn more about hypotheses here https://brainly.com/question/14042255

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