SAT scores were originally scaled so that the scores for each section were approximately normally distributed with a mean of 500 and a standard deviation of
100. Assuming that this scaling still applies, Use a calculator to find the probability
that a randomly-selected SAT student scores more than 620.

A. 38.4%
B. 11.6%
C. 61.6%
D. 88.4%

Ineed on this question me get the answer

The table below shows the approximate masses of a dust particle and a grain of pollen. dust particle 0.000000778 g grain of pollen 0.00000000155 g the mass of a dust particle can be estimated and written in the form a × 10^b, where a = 8 and b = the mass of a grain of pollen can be estimated and written in the form a × 10^b, where a = 2 and b = based on the estimates, the mass of a dust particle is approximately blank times larger than the mass of a grain of pollen.

Atoss of a 20-sided die is equally likely to be any integer between 1 and 20 inclusive. what is the variance? provide your answer to two decimal points.