Answer:
line QR
Step-by-step explanation:
Plane QRB is the front face. Plane TSR is the top face. The planes intersect at the top front edge, line QR.
Answer:
19.35% probability that five will have completed four years of college
Step-by-step explanation:
For each individual chosen, there are only two possible outcomes. Either they have completed fourr years of college, or they have not. The probability of an adult completing four years of college is independent of any other adult. So the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
28% of individuals
This means that 
For a sample of 15 individuals, ages 25 and older, what is the probability that five will have completed four years of college?
This is P(X = 5) when n = 15. So


19.35% probability that five will have completed four years of college
The exponential distribution is:

where

The probability we want is how likely will a dvd player last more than 8 years, given it has already lasted 5 years
To find this, you use conditional probability.

where A is P(x>8) and B is P(x>5)
To find these probabilities, integrate over the distribution:

Sub into conditional probability formula:

Final Answer: Given a dvd player is more than 5 years old, the probability that it will last another 3 more years is about 54.9%
Answer:
1800 miles
Step-by-step explanation:
No. of miles driven by Mr. Thomas in May = 75
It is given that miles driven in July is 6 times of miles driven by Mr. Thomas in May(75 miles).
Thus
No. of miles driven by Mr. Thomas in July = 6 * No. of miles driven by Mr. Thomas in May = 6*75 = 450 miles.
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Another condition given that miles driven in June is 4 times of miles driven by Mr. Thomas in July(450miles as calculated above).
Thus
No. of miles driven by Mr. Thomas in June = 4 * No. of miles driven by Mr. Thomas in July = 4* 450 miles = 1800 miles.
No. of miles driven by Mr. Thomas in June is 1800 miles.