TABLE 12-13 Recent Studies Have Found That American Children Are More Obese

Multiple Choice

TABLE 12-13
Recent studies have found that American children are more obese than in the past.The amount of time children spent watching television has received much of the blame.A survey of 100 ten-year-olds revealed the following with regards to weights and average number of hours a day spent watching television.We are interested in testing whether the mean number of hours spent watching TV and weights are independent at 1% level of significance.
-In testing for differences between the median of two independent populations,the null hypothesis is

A) H₀ : M_D = 0.
B) H₀ : M_D ≠ 0.
C) H₀ : M₁ - M₂ = 0.
D) H₀ : M₁ - M₂ ≠ 0.