In a data set, the number that appears the most is called the

Mode  

Step-by-step explanation:

The mode of a data set is the value that appears most often.

Mean is wrong. If you add all the values and divide the sum by the number of values, you get the mean.

Median is wrong. If you arrange the values in numerical order, the median is the value in the middle.

the mode

Explanation: the mode is the number that appear the most in any data set

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.