The random variable x represents the number of boys in a family of three children. Assuming that boys and girls are equally likely, find the mean and standard deviation for the rand variable x. X P(x) 0.125 0 1 0.375 2 0.375 3 0.125 O A. mean: 1.50; standard deviation: 0.87 OB. mean: 1.50; standard deviation: 0.76 OC. mean: 2.25; standard deviation: 0.87 O D. mean: 2.25; standard deviation: 0.76

A given distribution has a population mean, μ, of 106 and a population standard deviation, σ, of 11.  What z-score would be associated with the value x = 104?

A given distribution has a population mean, μ, of 137 and a population standard deviation, σ, of 15. What z-score would be associated with the value x = 110?

In a normal distribution, a data value located 1.5 standard deviations below the mean has Standard Score: Z= In a normal distribution, a data value located 1.9 standard deviations above the mean has Standard Score: Z = In a normal distribution, the mean has Standard Score: z =

f the standard deviation of a normally distributed population is 22.0 and we take a sample of size 4, then the standard error of the mean is

TF.15 The standard deviation of a random sample of the hourly wages of 18 post office employees is s = $3.38. Assuming normal distribution, find a 95% confidence interval for the standard deviation σ. Use X2 - distribution.

A normal distribution has mean 62.1 and standard deviation 2.42. Find the data value corresponding to the following value of z.   z= -1.33