AP Stats U6&U7 M/C 2nd Period

We have calculated a 95% confidence interval and would prefer for our next confidence interval to have a smaller margin of error without losing any confidence. In order to do this, we can:

• I only

• II only

• III only

• I and II

• I and III

Tags

CCSS.HSS.IC.B.4

A Type I Error occurs in which of the following situations?

• H_A is rejected and the null hypothesis is true.

• H_O is rejected and the null is false.

• H_O is rejected and the null is true.

• The P-Value is too small to reject the null.

• The alpha level is too small and so the null is rejected.

The manager of an orchard expects about 70% of his apples to exceed the weight requirement for “Grade A” designation. At least how many apples must he sample to be 90% confident of estimating the true proportion within ±4%?

• 19

• 23

• 89

• 356

• 505

Which of the following is true about Student’s t-models?

• I only

• I and II

• I and III

• II and III

• I, II, and III

A professor was curious about her students’ grade point averages (GPAs). She took a random sample of 15 students and found a mean GPA of 3.01 with a standard deviation of 0.534. Which of the following formulas gives a 99% confidence interval for the mean GPA of the professor’s students?

• $3.01\pm2.947\left(\frac{0.534}{\sqrt{15}}\right)$

• $3.01\pm2.977\left(\frac{0.534}{\sqrt{15}}\right)$

• $3.01\pm2.576\left(\frac{0.534}{\sqrt{15}}\right)$

• $3.01\pm2.947\left(\frac{0.534}{\sqrt{14}}\right)$

• $3.01\pm2.977\left(\frac{0.534}{\sqrt{14}}\right)$

Tags

CCSS.HSS.IC.B.4