Answer:
is it from a text book
Step-by-step explanation:
Answer:
a) 33.33%)
b) 135 minutes
c) 8.66 min
d) 50%
Step-by-step explanation:
a) the probability for a uniform distribution is
P(b<X<a) = (a-b)/(c-d) , where c and d are the maximum and minimum values
therefore the probability that the flight is more than 140 minutes ( and less than 150 since it is the maximum value)
P(140<X<150) = (a-b)/(c-d) = (150-140)/(150-120) = 10/30 = 1/3 (33.33%)
b) the mean (expected value) for a uniform probability distribution is
E(X) = (c+d)/2 = (120+150)/2 = 135 minutes
c) the standard deviation for a uniform probability distribution is
σ²(X)= (c-d)²/12 = (150-120)²/12 = 75 min²
σ = √75 min² = 8.66 min
b) following the same procedure as in a)
P(120<X<135) = (a-b)/(c-d) = (135-120)/(150-120) = 15/30 = 1/2 (50%)
Answer:
<h2> In 8 hours he will set 1200 bricks</h2>
Step-by-step explanation:
In this problem, we are expected to estimate the number of bricks he can set in 8 hours.
let us convert hours to minutes we have
60 min make 1 hour
x min make 8 hours
cross multiply
x= 60*8
x= 480 min
We are assuming the same rate with which he sets 2.5 brick is the same as the rate with which he will set bricks for the 8 hours windows
so if the bricklayer sets
2.5 bricks in 1min
y bricks in 480 min
Cross multiply we have
y=2.5*480
y= 1200 bricks
hence in 8 hours, he will set 1200 bricks
Answer:
The correct answer is B. George’s computer is expected to have a value of $25 greater.
Step-by-step explanation:
Since Chelsea bought a computer on Monday for $ 1,300, and its value is predicted to decrease by $ 250 per year, while her brother George also bought a computer on Monday, and the function g (x) = 1,100 - 175x predicts how the value of his computer is expected to change after x years, to determine whose computer is expected to have a greater value when it is 3 years old, and how much greater will it be, the following calculation must be performed:
Chelsea:
1,300 - (250 x 3) = X
1,300 - 750 = X
550 = X
George:
1,100 - (175 x 3) = X
1,100 - 525 = X
575 = X
Therefore, George’s computer is expected to have a value of $ 25 greater.
