Answer:
a. E(x) = 3.730
b. c = 3.8475
c. 0.4308
Step-by-step explanation:
a.
Given
0 x < 3
F(x) = (x-3)/1.13, 3 < x < 4.13
1 x > 4.13
Calculating E(x)
First, we'll calculate the pdf, f(x).
f(x) is the derivative of F(x)
So, if F(x) = (x-3)/1.13
f(x) = F'(x) = 1/1.13, 3 < x < 4.13
E(x) is the integral of xf(x)
xf(x) = x * 1/1.3 = x/1.3
Integrating x/1.3
E(x) = x²/(2*1.13)
E(x) = x²/2.26 , 3 < x < 4.13
E(x) = (4.13²-3²)/2.16
E(x) = 3.730046296296296
E(x) = 3.730 (approximated)
b.
What is the value c such that P(X < c) = 0.75
First, we'll solve F(c)
F(c) = P(x<c)
F(c) = (c-3)/1.13= 0.75
c - 3 = 1.13 * 0.75
c - 3 = 0.8475
c = 3 + 0.8475
c = 3.8475
c.
What is the probability that X falls within 0.28 minutes of its mean?
Here we'll solve for
P(3.73 - 0.28 < X < 3.73 + 0.28)
= F(3.73 + 0.28) - F(3.73 + 0.28)
= 2*0.28/1.3 = 0.430769
= 0.4308 -- Approximated
Answer
greater than $1.
Step-by-step explanation:
the price of apples per pound is $1.37, therefore, the price per pound of apples is greater than $1.
Let
be the amount of parts the student answered correctly. Suppose that
is a function between
and the score of a student's project. As the student initially receives a fixed
points for turning the project in and
points for each correct part, the function is initially:
When the students receive
points for each correct part, the coefficient of
changes, as the amount of points received per correct answer increases. Thus:
.
.1 Simplify: 5n(2n3+n2+8)+n(4-n).
Solution:
5n(2n3+n2+8)+n(4-n).
= 5n × 2n3 + 5n × n2 + 5n × 8 + n × 4 - n × n.
= 10n4 + 5n3 + 40n + 4n – n2.
= 10n4 + 5n3 + 44n – n2.
= 10n4 + 5n3 – n2 + 44n.
Answer: 10n4 + 5n3 – n2 + 44n
Answer:
DE = 13.4 cm (to 1 decimal place)
Step-by-step explanation:
Given: ABCD is a square
BC = AC = 12 cm (opposite sides of a square are congruent)
E is midpoint of BC (given)
BE = EC = 12/2 = 6 cm
CD = AB = 12 cm (opposite sides of a square are congruent)
angle ECD is a right angle (interior angles of a square are 90 deg.)
Consider right triangle ECD
DE = sqrt(EC^2+CD^2) ............. pythagorean theorem
= sqrt(6^2+12^2)
= sqrt ( 36+144 )
= sqrt (180)
= 2 sqrt(45)
= 13.416 (to three dec. places)
