Answer:
a) P(z<-0.66) = 0.2546
b) P(-1<z<1) = 0.6826
c) P(z>1.33) = 0.9082
Step-by-step explanation:
Mean = 300
Standard Deviation = 75
a) Less than 250 hours
P(X<250)=?
z = x - mean/ standard deviation
z = 250 - 300 / 75
z = -50/75
z = -0.66
P(X<250) = P(z<-0.66)
Looking for value of z = -0.66 from z score table
P(z<-0.66) = 0.2546
b. Between 225 and 375 hours
P(225<X<375)=?
z = x - mean/ standard deviation
z = 225-300/75
z = -75/75
z = -1
z = x - mean/ standard deviation
z = 375-300/75
z = 75/75
z = 1
P(225<X<375) = P(-1<z<1)
Looking for values from z score table
P(-1<z<1) = P(z<1) - P(z<-1)
P(-1<z<1) = 0.8413 - 0.1587
P(-1<z<1) = 0.6826
c. More than 400 hours
P(X>400) =?
z = x - mean/ standard deviation
z = 400-300/75
z = 100/75
z = 1.33
P(X>400) = P(z>1.33)
Looking for value of z = 1.33 from z-score table
P(z>1.33) = 0.9082
15,785 and well try to do your best haha
10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000:10 in a middle school case.
0.4n-3(n+0.1)
0.4n-3n-0.3
-2.6n-0.3
