Refer to the accompanying figure. Complete parts (a) through (d) below. Click the icon to view the figure. a. Why are the four graphs in column (a) all centered at the same place? All four graphs are centered at the same place because the mean of the sampling distribution, , is equal to the population mean, or u, and normal distributions are centered at their means. b. Why does the spread of the graphs diminish with increasing sample size? How does this result affect the sampling error when you estimate a population mean, u, by a sample mean, x? Because as n increases, This fact results in a diminishing of the spread because the spread of a sampling distribution is determined by As a consequence, the larger the sample size, the is the likelihood for small sampling error.Sampling distributions of the sample mean for (a) normal, (b) reverse-j-shaped, and (c) uniform variables distribution of X X X the variable sampling distribution XI X X n =2 sampling distribution X X *1 n = 10Sampling distributions of the sample mean for (a) normal, (b) reverse-j-shaped, and (c) uniform variables sampling distribution X n = 10 sampling distribution X n = 30 X (a) (b) (c)