Question

3. A research team wants to know if reading fiction versus non-fiction books boosts creativity. They hypothesize that there will be a difference in levels of creativity between individuals who read a novel versus a biography once a week for two months. They have one sample of college students (n₁=35) read a novel per week for two months, and they have a second sample of college students (n₂=35) read a biography per week for two months. The novel reading sample score an average of 7.8 (s₁= 2.4) on a creativity scale that ranges from 1-10, and the biography reading sample score an average of 5.3 (s₂= 2.1).

b. If this were a two-tailed test with alpha = .05, what would the critical value be? (.5 points)

c. Please calculate the test statistic (2 points)

Answer 1

b) For n₁ + n₂ - 2 = 35 + 35 - 2 = 68 degrees of freedom, as we are testing here whether there will be a difference in levels of creativity between individuals who read a novel versus a biography once a week for two months, therefore we get from the t distribution tables here:
P( t₆₈ < 1.995) = 0.975

which means due to symmetry, we have here:
P( -1.995 < t₆₈ < 1.995) = 0.95

Therefore 1.995 is the required critical value for 5% level of significance here.

c) The standard error here is computed as:

The test statistic now is computed here as:

Therefore 4.64 is the required test statistic value here.