The mean height of 3 boys is 150 centimeters. the mean height of 2 girls is 145 centimeters. find the mean height of the 5 students.

It’s 147.5.

When you calculate the average you have to add all the numbers and then divided the answer by the amount of numbers.

Ex. The average of 4, 7, 9, 1, 3, and 10 is 5.66 because 4 + 7 + 9 + 1 + 3 + 10 is 34 and then you divide by 6 (because there are 6 numbers) which is 5.66.

In order to do this you need to know all of these
10^0=1
10^1=10
10^2=100
10^3=1000
10^4=10000

The first one on there is correct, however the second one would be 483.1/10=48.31
The third one is 
483.1/100=4.831
The fourth one is 
483.1/1000= .4831
The fifth one is 
483.1/10000= .04831

Hope this helps