Problem Set 3.3: z Test
Criterion: Compute a z touchstone to gain a determination environing a illustration.
Data: The balance (mean) altitude for adult women is 65 inches, and the criterion inconsequence is 3.5 inches. Given the women you lowerstand, you judge this compute is low; so, you proceedings the altitudes of 25 of your effeminate friends. The balance altitude of your 25 friends is 66.84 inches.
Portion of the Usual Flexion Table
z
Area
z
Area
z
Area
z
Area
1.92
.9726
2.27
.9884
2.62
.9956
2.97
.9985
1.93
.9732
2.28
.9887
2.63
.9957
2.98
.9986
1.94
.9738
2.29
.9890
2.64
.9959
2.99
.9986
Instruction: Tally this: If your friends are usual a delegated-to-others illustration of adult effeminates, what is the appearance that your friends are so high?
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Problem Set 3.4: Refractory Variables (IVs) and Dependent Variables (DVs)
Criterion: Differentiate betwixt refractory and dependent variables.
Data: A researcher randomly assigns a class of adults to one of two diets plans (Diet Plan A or Diet Plan B), and she then measures the equality of power forfeiture each experiences in a two-week era.
Instruction: Tally the superveneing:
What is the IV in this consider?
What is the DV in this consider?
Problem Set 3.5: Hypotheses
Criterion: Write a directional-opinion supposition, nondirectional-opinion supposition, and vain supposition.
Data: A researcher is considering whether the equality of power forfeiture differs in alloticipants who supervene Diet Plan A versus those who supervene Diet Plan B.
Instruction: Write the superveneing:
a. A directional opinion supposition.
b. A nondirectional opinion supposition.
c. The vain supposition.
Problem Set 3.6: Errors and Significance: Likeness 1 and Likeness 2 Error
Criterion: Differentiate betwixt Likeness 1 and Likeness 2 untruth.
Data: It is an recurrent event that in the unconcealed population, men criticize further on balance than women. In a consider, you randomly illustration 100 men and 100 women, you proceedings each alloticipant's weight, and you furnish that there is no indicative disagreement in power grounded on gender.
Instruction: Tally the following:
Given that a disagreement really does pause in the population, what likeness of untruth is this (Type 1 or Likeness 2)? Teach your toweringy.
Problem Set 3.7: Errors and Significance: Likeness 1 and Likeness 2 Error
Criterion: Differentiate betwixt Likeness 1 and Likeness 2 untruth.
Data: In unconcealed, men and women do not differ on IQ. However, as allot of your consider, you establish that women scored significantly loftier than men on IQ.
Instruction: Tally the following:
Given that you establish a disagreement in your consider where none pauses in the unconcealed population, substantiate the untruth (Type 1 or Likeness 2) and teach your toweringy.
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Problem Set 3.8: Supposition Testing and the z Score.
Criterion: Evaluate a vain supposition grounded on analysis of basis.
Data: Joan is 72 inches high. The balance (mean) altitude for adult women is 65 inches, and the criterion inconsequence is 3.5 inches.
Instructions:
a. State the vain supposition.
b. State the opinion supposition.
c. Tally this: Joan is loftier than what percentage of women in the population? (Hint: Judge z score and area lower the usual flexion.)
d. Tally this: Given Joan's altitude as compared to the population balance, do you forebode to repel the vain supposition? Teach your toweringy.
Problem Set 3.9: One-Sample t Test
Criterion: Hand compute a one-illustration t touchstone.
Data: Rex’s Flower Shop advertised vigorous cut roses that last longer than other roses. The balance vase duration for a rose is 8 days. The superveneing is a illustration of the compute of vase duration days for 9 bouquets of roses from Rex’s Flower Shop: 8, 6, 12, 11, 8, 9, 14, 15, 10.
Instruction: Complete the superveneing:
a. State the nondirectional supposition.
b. State the precarious t for α = .05 (two tails).
c. Compute t. Show your effort.
d. Answer: Is the vase duration of Rex’s roses indicatively divergent than the population balance? Explain.