In a chi-square test of homogeneity of proportions we test the claims that Group of answer choices Different populations have the same proportions of individuals with the same characteristics. The proportion of a population having a given characteristic is based on the homogeneity of the population. Across a single sample the proportion of individuals with the same characteristic is the same as the population. The proportion of individuals with a given characteristic doesn't change over time.

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.