Confirmed cases of West Nile virus in birds for a sample of six ...

[tingc95]

Confirmed cases of West Nile virus in birds for a sample of six counties in the state of Georgia are shown below. County Cases Catoosa 6 Chattooga 3 Dade 3 Gordon 5 Murray 3 Walker 4 We are interested in testing the following hypotheses regarding these data: H0:   3 Ha:  > 3
 a. Compute the mean and the standard deviation of the sample.
  b. Compute the standard error of the mean.
  c. Determine the test statistic.
  d. Determine the p-value and at 95 confidence, test the hypotheses.

Question 2

You are given the following information obtained from a random sample of 4 observations. 25 47 32 56 You want to determine whether or not the mean of the population from which this sample was taken is significantly different from 48 . (Assume the population is normally distributed.)
 a. State the null and the alternative hypotheses.
  b. Determine the test statistic.
  c. Determine the p-value; and at 95 confidence test to determine whether or not the mean of the population is significantly different from 48.

[cdmart10]

Answer to Question 1

a. 4 and 1.265 (rounded)
b. 0.5164
c. t = 1.94 (rounded)
d. p-value is between 0.05 and 0.1; reject H0 and conclude that the mean of the population is significantly more than 3.

Answer to Question 2

a. H0:  = 48
Ha:   48
b. t = -1.137
c. p-value is between 0.2 and 0.4 (two tailed); do not reject H0.