a.the sample mean becomes smaller and the sample variance becomes larger.

b.the sample mean becomes larger and the sample variance becomes smaller.

c.neither the sample mean nor the sample variance remains constant.

d.both the sample mean and sample variance become larger.

11.The t distribution can be used with small samples for establishing confidence intervals for the population mean, provided that the population distribution

a.has a known variance.

b.is normally distributed.

c.is symmetric.

d.is continuous