In Chi ^ 2 tests, a large difference between observed and expected frequencies increases chances that the null hypothesis will be rejected and the outcome of the test will be not significant. B. decreases chances that the null hypothesis will be rejected and the outcome of the test will be significant. C. increases chances that the null hypothesis will be rejected and the outcome of the test will be significant.

A 2012 article in the New England Journal reports the results of a randomized trial to assess the association between regular usage of asthma medication prior to turning 18 years old, and height at age 18 years. As per the authors, "From December 1993 through September 1995,we randomly assigned 1041 children between the ages of 5 and 13 years with mild-to-moderate asthma to one of three study groups in the double-blind, placebo-controlled CAMP trial." (reference: Kelly H, et al. Effect of Inhaled Glucocorticoids in Childhood on Adult Height. New England of Medicine (2012). 367 (10)) The random assignment groups were Budesonide, Nedocromil and placebo. The following graphic shows the distribution of female and male participant heights at different times in the study follow-up, presented for the Budesonide and placebo samples. A Unadjusted Height Distribution 200- Budesonide Placebo 190- 180- 170- 160- 150- 140- 130- 120- 110- 100- Trial entry 2 Yr Trial end Adult Trial entry 2 Yr Trial…

What is the variance of random variables X, the outcome of rolling a fair die?

A pooled variance estimate is useful for two-sample hypothesis tests of a normal mean when the underlying population variances are considered unequal. True False