Question

QUESTION 13

1. A middle school art teacher knows that the average on a creativity test is µ = 200 with a standard deviation ofσ = 50. She wants to know if the average of M = 215 for a sample of 49 students from her classes is higher than 200. Compute the z score (the test statistic) for the sample mean.

	a.	+0.30
	b.	+0.31
	c.	+2.10
	d.	+14.70

QUESTION 14

A middle school art teacher knows that the average on a creativity test is µ = 200 with a standard deviation ofσ = 50. She wants to know if the average of M = 215 for a sample of 49 students from her classes is higher than 200. Can she reject her null hypothesis using an alpha level, α = .05 in one tail?

	a.	Yes, because the probability of obtaining a mean of 215 or higher if the null is true is about 0.0179.
	b.	Yes, because the probability of obtaining a mean more extreme than 215 if the null is true is about 0.0358
	c.	No, because the probability of obtaining a mean of 215 or higher if the null is true is about 0.3821
	d.	No, because the probability of obtaining a mean more extreme than 215 if the null is true is about 0.7566

QUESTION 15

1. A middle school art teacher knows that the average on a creativity test is µ = 200 with a standard deviation ofσ = 50. She wants to know if the average of M = 215 for a sample of 49 students from her classes is higher than 200. Another way to decide whether or not to reject the null hypothesis is to compare the test statistic to a critical value. What is the critical z score for this hypothesis test, with alpha set as α = .05 (one-tailed)?

	a.	1.65
	b.	-1.65
	c.	1.96
	d.	-1.96

QUESTION 16

1. A middle school art teacher knows that the average on a creativity test is µ = 200 with a standard deviation ofσ = 50. She wants to know if the average of M = 215 for a sample of 49 students from her classes is higher than 200. Compute the effect size (d).

	a.	0.04
	b.	0.08
	c.	0.31
	d.	0.30

Answer 1

Solution

Given,

n = 49

Xbar = 215

µ = 200

σ = 50

Q13

Test statistic:

Z = (√n)(Xbar - µ₀)/σ = 2.1 Option c Answer 1

where n = sample size;

Xbar = sample average;

σ = known population standard deviation.

Q14

p-value = 0.0179 Option a Answer 2

[Under H₀, Z ~ N(0, 1)

p-value = P(Z > Zcal)]

Q15

Critical value = 1.645 Option a Answer 3

[Under H₀, Z ~ N(0, 1)

Critical value = upper α% point of N(0, 1).]

Q16

Effect size (d) = 0.3 Option d Answer 4

[Effect size (d) = Mean difference/standard deviation]

DONE