Two cities A and B are 650 km away. A car leaves A at 8:15 a. m. and arrives at 2:32 p. m. What is the time it took for the trip and what is the mean scalar speed in km / h?

Asynthetic fiber used in manufacturing carpet has tensile strength that is normally distributed with mean 75.5 psi and standard deviation 3.5 psi. how is the standard deviation of the sample mean changed when the sample size is increased from n equals 8 to n equals 47