Question

Question 6.3.14 In an article titled "Unilateral Nostril Breathing Influences Lateralized Cognitive Performance" that appeared in Brain and Cognition (1989), researchers Block et al. published results from an experiment involving assessments of spatial and verbal cognition when breathing through only the right versus left nostril. The subjects were 30 male and 30 female right handed introductory psychology students who volunteered to participate in exchange for course credit. Initial testing on spatial and verbal tests revealed the following summary statisticS Note that the scores on the spatial task can range from 0 to 40, whereas those on the verbal task can go from 0 to 20. The distributions are not strongly skewed on either scale or for males or females, Spatial Verbal Sex Mean SD 0.202.70 10.90 3.00 7.80 2.5015.10 3.40 SD Mean Male Female

Answer 1

The probability of obtaining t statistic of difference in mean scores of males and females with regard to performance on verbal assessments is smaller is less than 0.0001 if null hypothesis is true.

Two-Sample T-Test and CI

Sample N Mean StDev SE Mean
Male 30 10.90 3.00 0.55
Female 30 15.10 3.40 0.62

Difference = mu (1) - mu (2)
Estimate for difference: -4.200
95% CI for difference: (-5.857, -2.543)
T-Test of difference = 0 (vs not =): T-Value = -5.07 P-Value = 0.000 DF = 58
Both use Pooled StDev = 3.2062
95% CI for difference in mean scores of males and females: (-5.86, -2.54)

We have strong evidence that the average verbal score is significantly higher for women than men. This is not necessarily a cause-and-effect conclusion, nor can the result be confidently generalized to a broader population since the sample was not obtained randomly from a larger population.