A study conducted in year 2002 found that the mean number of children under 18 per household in a certain community was 1.7. A statistician is trying to determine whether this number has changed in the last 6 years. She declares the null and alternative hypotheses to be: Null: The mean number of children per household in 2002 is equal to 1.7; Alternative: The mean number of children per household in 2002 is not equal to 1.7. Which of the following statements is true about this test? a. This is a step-tailed test.
b. This is a left-tailed test.
c. This is a two-tailed test.
d. This is a right-tailed test.