Range = 38 Mean = 28.5555556 Variance = 147(253)/(300) Standard deviation = 12.27 ⠀ ⠀ 19, 40, 42, 7, 29, 45, 23, 17, 35 ⠀

Please help me understand the problem. Is the given standard deviations 6, and 7? I know I need to use the unit normal table, and shade the curve. But how? Thanks.

True or False. The standard deviation of the mean is less than the sample standard deviation because it estimates the variation of averages, which are more precise than single observations.

Explain what restriction of range is and what it tends to do to the magnitude of a correlation.