Question

A. A researcher wants to know whether identical twins differ in their self-confidence. Specifically, she wants to know whether the twin that was born first benefits from being "the older" twin. Which type of t-test would be most appropriate for comparing the average self-confidence of older twins to the younger twins?

B. Kruger and Dunning (1999) published a paper called "Unskilled and Unaware of It", in which they examined the hypothesis that people who perform badly on tasks are unaware of their general logical reasoning skills. Each student estimated at what percentile he/she scored on a test of logical reasoning-- the eleven students who scored in the bottom 25% estimated on average that they were in the 68th percentile! What type of t-test would be most appropriate to test the hypothesis that their average estimated percentile ranking (68%) was significantly greater than 50%?

C.

CHECK ALL THAT ARE CORRECT: Which of the following are true about repeated-measures t-tests, compared to independent-samples t-tests?

Group of answer choices

Reduces variance due to individual differences

Better for studying change over time

Requires fewer participants

Answer 1

Here we are given that a researcher wants to know whether identical twins differ in their self-confidence. Specifically, she wants to know whether the twin that was born first benefits from being "the older" twin. We have to state Which type of t-test would be most appropriate for comparing the average self-confidence of older twins to the younger twins

A paired sample T test , sometimes called dependent sample t test , is a statistical procedure used to determuine whether the average difference between 2 sets of observation is zero.

thus here we select a paired t test sice we have to compare the average self confidence of the older twin to the younger twin who are dependent samples.