In testing a hypothesis about two population means, if the t distribution is used, which of the following assumptions is required? Select one:
a. Both populations are normally distributed.
b. The standard deviations are not the same.
c. Both population means are the same.
d. The sample sizes are equal.

Rick is a toddler with an easy temperament and active nature. people are often seen stopping to talk to him in supermarkets and parks where his mother takes him in the evenings because he smiles willingly at other children and adults. this aspect of rick’s behavior most likely reflects a(n) active genotype–environment interaction suppressive genotype-environment interaction passive genotype–environment interaction evocative genotype–environment interaction

Who is responsible for maintaining a balanced state budget

How did economics delay scientists' first attempts for conservation in each story? describe the political actions that led to successful conservation in both stories. i have them all done but these two. none of my teachers are responding and i just need . i can show both stories.