Answer:
a) P(Y > 76) = 0.0122
b) i) P(both of them will be more than 76 inches tall) = 0.00015
ii) P(Y > 76) = 0.0007
Step-by-step explanation:
Given - The heights of men in a certain population follow a normal distribution with mean 69.7 inches and standard deviation 2.8 inches.
To find - (a) If a man is chosen at random from the population, find
the probability that he will be more than 76 inches tall.
(b) If two men are chosen at random from the population, find
the probability that
(i) both of them will be more than 76 inches tall;
(ii) their mean height will be more than 76 inches.
Proof -
a)
P(Y > 76) = P(Y - mean > 76 - mean)
= P(
) >
)
= P(Z >
)
= P(Z >
)
= P(Z > 2.25)
= 1 - P(Z ≤ 2.25)
= 0.0122
⇒P(Y > 76) = 0.0122
b)
(i)
P(both of them will be more than 76 inches tall) = (0.0122)²
= 0.00015
⇒P(both of them will be more than 76 inches tall) = 0.00015
(ii)
Given that,
Mean = 69.7,
= 1.979899,
Now,
P(Y > 76) = P(Y - mean > 76 - mean)
= P(
)) >
)
= P(Z >
)
= P(Z >
))
= P(Z > 3.182)
= 1 - P(Z ≤ 3.182)
= 0.0007
⇒P(Y > 76) = 0.0007
Answer: The product of (3x+7) and (x-7) equals 3x^2 + 28x + 49
Step-by-step explanation:
To find the product of (3x+7) and (x-7) means to multiply both variables: To multiply both variables, we first multiply 3x by the expression, x - 7, then multiply 7 by the expression, x - 7.
(3x × x) +( 3x × 7) + (7 × x) + ( 7 × 7)
= 3x^2 + 21x + 7x + 49
= 3x^2 + 28x + 49
Answer:
x=1
Step-by-step explanation:
you would substitute the first equation in for the y in the second equation
x + 2x+3 =6
then you would combine the x's
3x +3 = 6
Then you would move the 3 to the other side with the six
3x =6-3 3x = 3
Then finally you would divide the three
3x/3 = 3/3 x=1
Answer:
Step-by-step explanation:
2*4+3= 11/4
2*2+1= 5/2
11/4 * 5/2 = 55/8
Simplified 6 7/8