Change each of these test scores to: i.) fractions in their lowest terms.
ii.) percentages.
Show your working.
a.) 21 out of 50.
b.) 105 out of 150.
c.) 45 out of 75.
d.) 118 out of 200.

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).

Which graph represents the solution set for the given system of inequalities? x+2y< 3 x+y> 4 3x-2y> 4

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?