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## #1 Help Me ! » statistics » 2012-10-03 01:45:21

cassrl
Replies: 1

A standard measure of test anxiety is knnown to produce a u=19.  In the sample you draw of 86 the mean is equal 17.5 with a standard deviation s=10.

a-Use a level of 0.05 to test the hypothesis that the mean is less than 19.
b-find the 95% one sample confidence interval for the mean.

## #2 Help Me ! » statistics » 2012-10-03 01:40:59

cassrl
Replies: 1

Mean proportion of individuals is p=0.30, sample size is 25 from this population, what fraction will have a sample porportion of 0.20 or lower?

## #3 Help Me ! » statistics » 2012-10-03 01:38:57

cassrl
Replies: 1

X score is normally distibuted with mean 90 and standard deviation 23 Find:
A-the probability of a score between 76 and 117
b-probability that the mean score of a sample of n=64 is greater than 97

## #4 Help Me ! » statistics » 2012-10-03 01:33:44

cassrl
Replies: 1

Top 12% of the class will an A.  Mean grade is 72 and the standard deviation is 10.  What grade would you need to earn an A?