what am I doing wrong here with the normal distribution? (my professor said the 50 or more needs to be 49.5)

#14 Ice Cream: FlavorsWhat is your favorite ice cream flavor?For people who buy ice cream, the all-time is still vanilla.About 25% of ice cream sales are vanilla.Chocolate accounts for only 9% of ice cream sales.Suppose that 175 customers go to a grocery store today to buy ice cream.

(a)What is the probability that 50 or ore will buy vanilla?

Mean =np=175(0.25)=43.75

=43.75

=

=

=

=5.7282

P(>50)

P(>50)=1 -P (x<50)

1-P( x- < (50- )

=1- P( x- < (49.5- 43.75)

5.7282

=5.75

5.7282

=1.0038

1-P(z<1.0038)

=1- 1

P(x>50)=1.587

***my professor said the 12 or more needs to be 11.5

(b)What is the probability that 12 or more will buy chocolate?

N= 175

P=0.09

=n.p

175x0.09=

=15.75

=

=

=

=3.79

P(r>12)

P(r>12)=P(x>11.5)

1-P(x<11.5)

1-P(z < 11.5-15.75)

3.79

1-P(z < -4.25)

3.79

1-P(z< - 1.121)

=1 - 1.121

P(x>12)

=0.121