Question

1. Lucy always uses an alpha level of 0.01 (two-tailed). Charlie always uses an alpha level of 0.05 (two-tailed). Which researcher is more likely to make a Type I Error.

   Lucy or charlie?

2. A researcher is interested in whether blood pressure decreases among adults who eat dark chocolate. The mean systolic blood pressure of the population is 135 with a standard deviation of 15. She tests a sample of 100 adults who eat dark chocolate and finds their mean systolic blood pressure to be 120. What is the null hypothesis?

-μ = 135

-μ ≠ 135

-μ  > 135

-μ ≥ 135

3. According to Cohen's d conventions, which of the following would be considered to be a medium effect size?

. -0.55

. 0.81

. -0.98

. 0.17

4. With α = 0.05, what is the critical t value for a one-tailed test with n = 15?

t = 1.761

t = 1.753

t = 2.145

t = 2.131

5. What z-score values form the boundaries for the middle 68% of a normal distribution?

z = +0.2 and z = - 0.2

z = +0.4 and z = - 0.4

z = +0.8 and z = - 0.8

z = +1.0 and z = - 1.0

Answer 1

(1)

Correct option:

Charlie

Explanation:

The probability of making a Type I Error is .

(2)

Correct option:

μ ≥ 135

Explanation:

H0: Null Hypothesis: μ ≥ 135 ( blood pressure does not decrease among adults who eat dark chocolate)

HA: Alternative Hypothesis: μ < 135 ( blood pressure decreases among adults who eat dark chocolate)

(3)

Correct option:

-0.55

Explanation:

Value of d near 0.5 is considered medium.

(4)

Correct option:

t = 1.753

(5)

Correct option:

z = +1.0 and z = - 1.0