Question:These are questions that I need help with. Can you explain to me why they are what they are? This is my study guide.

Question 1:

What does it mean to say that the Cohen's d for a 2-group study is .3?

3% of the variance in one group is accounted for by the variance in the other group

the two group means are .3 standard deviations apart

the effect is large

the two groups are separated by .3 units

Question 2:

A study of the effect of sleeping position on mental clarity compared people who slept on their backs, on their stomachs, and on their sides. The ANOVA was significant and the ²was .24, meaning that

24% of the variance in sleeping position is explained by mental clarity

r²= .0576

24% of the variance in mental clarity is explained by sleeping position

the group means for the three different sleeping positions all differed by .24 points

Question 3:

When working with sample data, R²_adjustedis preferred over R²because R²_adjustedis

unbiased

analogous to²

less biased than R²

a measure of the proportion of the variance in Y accounted for by the variance in X

Question 4:

Jane wants to compare the average emotional intelligence of accountants, receptionists and CEOs. She administers a test of emotional intelligence that is known to be normally distributed in the population to random samples of 50 accountants, 50 receptionists and 50 CEOs. The variance of emotional intelligence is the same in all groups. She then conducts three independent samplest-tests comparing the accountants to the receptionists, the receptionists to the CEOs and the accountants to the CEOs. What is wrong with this study?

The assumption of population normality is violated

The assumption of homogeneity of variances is violated

A Type II Error has been made

The probability of a Type I error is greater than because multiple comparisons are being conducted

Question 5:

R²_adjustedis like the ²in that both are measures of

The number of standard deviations two means are separated by

the proportion of variance in one variable accounted for by its relationship with another variable

the significance of the independent variable

the significance of the dependent variable

Question 6:

Which of the following is NOT a required assumption for calculating inferential statistics of a regression?

Homogeneity of Variances: The variance of X must be equal to the variance of Y

Normality: The errors of prediction are distributed normally

Homoscedasticity: The variance around the regression line is the same for all values of X

Linearity: The relationship between the two variables is linear

Question 7:

A study looking at the relationship between time spent outdoors and BMI found that they were correlated at r=0.2 with a sample of 102 people. What is the t for testing the significance of this correlation?

2.24

2.41

2.50

2.04

Question 8:

A study looked at the relationship between time spent outdoors and BMI. Which of the following is an appropriate test of the significance of the relationship?

t test of a correlation (r)

ANOVA

z test of a single group mean

Chi-square test of independence

Question 9:

A developmental psychologist was studying the effect of parenting style and gender on the temperament of children. The parents were classed as authoritative, authoritarian, or indulgent. The children were classed as either boys or girls. What was the design of the study?

3 (Parenting Style) x 1 (Temperament)

3 (Parenting Style) x 2 (Gender)

1 (Temperament) x 2 (Gender) x 3 (Parenting Style)

1 (Temperament) x 2 (Gender)

Question 10:

A researcher wanted to know if there was a relationship between Attachment Style and Relationship Status. He assessed the attachment style of 400 people and asked them about their relationship status. People were classed as either securely attached, avoidantly attached, or ambivalently attached, and as either single, dating casually, dating seriously, or married.

Which of the following is the best statement of the null hypothesis?

Attachment style affects relationship status

Attachment style and relationship status are related

Attachment style is unrelated to relationship status

People who are Securely Attached are less likely to be single than other people