To find a number between both decimals, what you can do is take the average of both numbers.
We have then:

Rewriting we have:

Therefore, the decimal obtained is a number between 0.4 and 0.5
Answer:
a decimal between 0.4 and 0.5 is:

To make a dot plot, make a numbered line and add dots above the numbers of the given ages. If there are more than one of the same number, add a dot above the dot already there.
See attached picture:
You have a 1/95 chance of pulling a pink rubber band. You have a 1/90 chance of pulling a brown rubber band
Just add the two equations together.
2b = 18
b = 18/2
b = 9
9 = k + 10
9 - 10 = k
k = - 1