The density of people (number of people per mile) during the evening rush hour for the 5 mile stretch along a certain sidewalk in New York is given by f(x), where x is the distance in miles north of the subway station. Which of the following gives the number of people on this 5 mile stretch from the subway?

5
a. ∫ f(x). dx
0

x
b. ∫ f(x). dx
0

x
c. ∫ f(x). dx
5

5
d. ∫ f(x). dx
x

a.  

Step-by-step explanation:

Since f(x) is the function for the populational density at a certain sidewalk for a 5 mile stretch, a definite integral of that function will yield the total number of people within the integration intervals. If we are interested in the number of people in the whole 5 mile stretch, we must integrate f(x) from x = 0 miles to x = 5 miles:

Therefore, the answer is alternative a.

24

step-by-step explanation:

the graph shows 30% of students walk. 80 students were questioned, so the number that said they walk is

30% × 80 = 0.30 × 80 = 24

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %