Answer:
Expected number of hours before the the group exits the building = E[Number of hours] = 3.2 hours
Step-by-step explanation:
Expected value, E(X) is given as
E(X) = Σ xᵢpᵢ
xᵢ = each variable
pᵢ = probability of each variable
Let X represent the number of hours before exiting the building taking each door. Note that D = Door
D | X | P(X)
1 | 3.0 | 0.2
2 | 3.5 | 0.1
3 | 5.0 | 0.2
4 | 2.5 | 0.5
E(X) = (3×0.2) + (3.5×0.1) + (5×0.2) + (2.5×0.5) = 3.2 hours
Hope this Helps!!!
33 and one third as a fraction would be either 33 1/3 or 100/3
Answer:
Don't really understand the question, but
We have the frequencies for each of the grades. We can estimate the number of students graded by adding all those frequencies. Let's call N the total number of grades:

We have then a total number of grades of 39.
The corresponding relative frequency for a grade is the ratio of the frequency to the total number of "samples", 39 in this case.
Then, for grade A, the relative frequency (RF) will be:

This will be the fraction of the total grades that are A. Represented as a percentage will be 10.26%, rounded to two decimal places.
Now, to complete the table we do the same for the other frequencies:
For grade B:

For grade C:

For grade D:

For grade F: