Suppose that someone claims that adult koalas on average eat

Suppose that someone claims that adult koalas, on average, eat no more than 400 grams of eucalyptus leaves per day. To test that claim, you head to Australia and collect information on a sample of 89 adult koalas and find that the mean daily amount eaten by them is 410 grams. The standard deviation is 40 grams. What is the lowest significance level at which we would reject the null hypothesis?

0.009175

0.020832

0.05

0.95

Solution

mu = 400

n =89 , x bar = 410, sigma =40

Calculate std error = 40/rt 89 = 4.240

t statistic = 400-410/4.240 = -2.3585

p value = 0.01028

As p value should be less than significance level for rejecting least significance level = 0.020832