Evelyn rolled two 1-6 number cubes 72 times. How many times should she predict she will roll a sum of 5?

to get a sum of 5, we could have

1 4
2 3
3 2
4 1
so, prob(sumof 5) = 4/36

expected sum of 5 in 72 tries
= (4/36)(72) = 8

To determine how many times Evelyn should predict she will roll a sum of 5, we need to know the probability of rolling a sum of 5 on two 1-6 number cubes.

To find the probability of an event, divide the number of favorable outcomes by the total number of possible outcomes.

For rolling two number cubes, each cube has 6 possible outcomes (numbers 1-6).

To get a sum of 5, the possible favorable outcomes are:
(1, 4), (2, 3), (3, 2), (4, 1) - total of 4 favorable outcomes.

Therefore, the probability of rolling a sum of 5 on two number cubes is:
4 favorable outcomes / 6 possible outcomes * 6 possible outcomes = 4/36 = 1/9.

Since Evelyn rolled the two number cubes 72 times, we can predict that she will roll a sum of 5 approximately:
(1/9) * 72 = 8 times.

Evelyn should predict she will roll a sum of 5 approximately 8 times.

To determine how many times Evelyn should predict she will roll a sum of 5 when rolling two 1-6 number cubes, we need to consider the probability of rolling a sum of 5.

First, let's find all the possible outcomes when rolling two 1-6 number cubes. Each cube has six sides, so the total number of outcomes is 6 * 6 = 36.

Next, let's list down all the possible combinations that result in a sum of 5:
1 + 4
2 + 3
3 + 2
4 + 1

So, there are 4 possible combinations that result in a sum of 5 out of 36 possible outcomes.

To find the probability of rolling a sum of 5, divide the number of desired outcomes (4) by the total number of possible outcomes (36):
Probability = 4/36 = 1/9

Since Evelyn rolled the two number cubes 72 times, we can predict that she will roll a sum of 5 approximately (1/9) * 72 = 8 times.