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:
7/8=0.875 7/20=0.35 18/20=0.9 7/8=0.875 68/50=1.36 25/20=1.25 26/25=1.04 11/10=1.1 11/16=0.6875 9/16=0.5625 33/40=0.825 23/40=0.575 14/10=1.4 29/25=1.16 39/40=0.975
Step-by-step explanation:
Extraneous solutions, is answers that we get because of squaring both sides of the radical equation, but in reality, they are not going to be the solutions of the given equation.
(√(4x+41))²=(x+5)²
4x+41=x²+10x+25
x²+6x-16=0
(x-2)(x+8)=0
x1=2 , x2=-8,
And now we must to check them by substitution into initial equation
√(4x+41)=x+5
1) x=2, √(4*2+41)=2+5, √49=7, 7=7 true
2) x=-8, √(4*(-8)+41)=-8+5, √9 =-3 false,
so an extraneous solution x=-8
No no no no no no no no no