In a random sample of 25 samples of gasoline sold as 87 octane, the mean (R+M)/2 octane rating was 87.3 with a standard deviation of 0.59. Use this sample to test the claim that, for all gasoline sold...

In a random sample of 25 samples of gasoline sold as 87 octane, the mean (R+M)/2 octane rating was 87.3 with a standard deviation of 0.59. Use this sample to test the claim that, for all gasoline sold as 87 octane, the mean (R+M)/2 octane rating is 87. Use a 0.01 significance level.