Answer:
a) the probability of A students study for more than 10 hours per week
P(X>10) = 0.117
b) The probability that an student spends between 7 and 9 hour
P(7<x< 9) = 0.9522
Step-by-step explanation:
Step(I):-
Let 'X' be random variable of the normal distributed with a mean of 7.5 hours and standard deviation of 2.1 hours
mean of the Population is = 7.5 hours
standard deviation of the Population = 2.1 hours
Z = 1.1904
The probability of A students study for more than 10 hours per week
P(X>10) = 0.5-A(Z₁) = 0.5 -A(1.1904) = 0.5 - 0.3830 = 0.117
Step(ii):-
Put x=7
put x=9
The probability that an A student spends between 7 and 9 hour
P(7 < x< 9) = A(9) - A(7)
= 0.7142 +0.238
= 0.9522
Answer:
D) 180
Step-by-step explanation:
Keep in mind to properly use a percent you must set it to a decimal.
To do so simply move the . in 75. over to the left 2 times. Which will go to .75!
Now time to multiply 240 by .45.
240 x .45 =180