The probability distribution for a random variable x is given in the table.
X
- 10
-5
0
5
10
15
20
Probability
120
.15
.05
11
125
1
.15
Find the probability that -5

take the logarithm of both sides (the base of the log doesn't matter):

apply the exponent property - this says that :

distribute the log terms on both sides:

group like terms together:

divide through both sides by the coefficient on :

you can do some additional rewriting here using the properties of the logarithm to simplify things if you like:

15.36 per mile

but forgot to round

i am pretty sure

sample answer: you can determine whether each element of the domain is paired with exactly one element of the range. for example, if given a graph, you could use the vertical line test; if a vertical line intersects the graph more than once, then the relation that the graph represents is not a function.