Answer:
0.688 or 68.8%
Step-by-step explanation:
Percentage of high school dropouts = P(D) = 9.3% = 0.093
Percentage of high school dropouts who are white =
= 6.4% = 0.064
We need to find the probability that a randomly selected dropout is white, given that he or she is 16 to 17 years old. This is conditional probability which can be expressed as: P(W | D)
Using the formula of conditional probability, we ca write:

Using the values, we get:
P( W | D) = 
Therefore, the probability that a randomly selected dropout is white, given that he or she is 16 to 17 years old is 0.688 or 68.8%
Given series is 2.4,-4.8,9.6,-19.2
To find whether it has common difference or common ratio let us find few differences and few ratios of consecutive terms.
Common difference of first 2 terms = 2nd term - first term = -4.8-2.4 = -7.2
Common difference of 2nd and 3rd terms = 3rd term - 2nd term = 9.6-(-4.8) = 14.4
Since those common differences are not equal the given series does not have common difference at all.
To check if it has common ratio or not let us find few ratios of consecutive terms.
Common ratio of first 2 terms =
= 
Common ratio of 2nd and 3rd terms = 
So, the given series has common ratio as -2.0