Question

1. Which of the following does a box plot not display?

a. The range

b. The interquartile range

c. The lower quartile

d. The mean

2. You have income data for your entire customer database. Some of your clients are far wealthier than others. Which of the following do outliers least affect?

a. The range

b. The mean

c. The median

d. The standard deviation

3. Some data were collected about consumer loyalty towards a (relatively) new brand of toilet roll – ‘Wipe-It’ (using a scale from 1 = I’d never go back to 10 = I will always purchase this brand). The sample was 15,467 people. When looking at the distribution, a skew of 1.23 (SE = 0.65) was identified. The mean rating was 4.78. Which of the following would be the best way to decide whether the skew in the example above is problematic for analysts at ‘Wipe-It’?

a. See if the z-score is bigger than 1.96 or smaller than –1.96.

b. See if the skew is significant at p < .05.

c. Use the Kolmogorov–Smirnov test.

d. None of the above, because of the large sample size.

4. Which of the following is not a transformation that can be used to correct skewed data?

a. Log transformation

b. Tangent transformation

c. Square root transformation

d. Reciprocal transformation

5. The Kolmogorov–Smirnov test can be used to test?

a. Whether data are normally distributed.

b. Whether group variance are equal.

c. Whether scores are measured at the interval level.

d. Whether groups means differ.

6. You are comparing customer lifetime value (CLV) in £s for two of your firm’s products – Mug-R and Jug-S. What does acceptance of the assumption of homogeneity mean for the two groups in this context?

a. The variance is twice as big for Mug-R than Jug-S.

b. Variances in the groups are approximately equal.

c. The variance across the groups is proportional to the means of those groups

d. The variance for both Mug-R and Jug-S is equal to the interquartile range

7. Which of the following tests whether variances are homogenous?

a. Levene’s test

b. Kolmogorov-Smirnov test

c. Durbin-Watson test

d. Both a and c

8. What is an outlier?

a. A set of data outside the data file.

b. A single score (e.g., participant response) that is very different from others.

c. A score derived from a participant who has lied.

d. A variable that cannot be quantified.

9. What does the assumption of independence tells us?

a. That we must never collect two sets of data from one person

b. That independent researchers must collect the data

c. That scores from one participant are free from influences from other participants

d. That the errors in our linear model must be independent

Answer 1

1) answer : mean

The box plot contains the five number summary they are :

Minimum

1st quartile

2nd quartile

3rd quartile

maximum

Also , IQR , RANGE etc,

2) answer : median

Since median is the middle value of the data set so it is least affected by the extreme values of the data set

3) answer : option d.

None of the above since the sample size is large.

4) answer : tangent transformation.

We have all the transformations like log(x) , sqrft(x) , log(x) etc....