Suppose you have a normal distribution with a mean of 6 and a standard deviation of 1. What is the probability of getting a Z score of exactly 1.2?

0
0.0
Think about the probability of a Z score of exactly 1.21009876353. It would be pretty low.
Because the normal distribution is continuous, the probability of any one specific point is 0.
You decide to use the normal distribution to approximate the binomial distribution. You want to know the probability of getting exactly 6 tails out of 10 flips. First you find the mean and SD of the normal distribution, and then you compute the area:

Because the normal distribution is continuous, the probability of any one specific point is 0. The solution is to round off and consider any value from 5.5 to 6.5 to represent an outcome of 6 tails. Using this approach, we figure out the area under a normal curve from 5.5 to 6.5.
false
at exactly 6
Use the simulation to calculate the probability of from 6 to 6 heads with N=10 and p = .5. Note the area that is shaded.
true
from 5.5 to 6.5
false
from 0 to 6
Use the simulation to calculate the probability of from 6 to 6 heads with N=10 and p = .5. Note the area that is shaded.
false
from 6 to 10
Use the simulation to calculate the probability of from 6 to 6 heads with N=10 and p = .5. Note the area that is shaded.
You decide to use the normal distribution to approximate the binomial distribution. You want to know the probability of getting from 7 to 13 heads out of 20 flips. You compute the area:

In order to include 7 flips, you need to start a little below it (6.5), and to include 13 flips, you need to go a little past it (13.5). So, you calculate the area from 6.5 to 13.5.
false
from 7.5 to 13.5
false
from 7.5 to 12.5
false
from 7 to 13
false
from 6.5 to 13
true
from 6.5 to 13.5
The normal approximation to the binomial is most accurate for which of the following probabilities?

It is most accurate for p=.5 because that makes the binomial distribution symmetric and closer to a normal distribution.
false
.2
Use the simulation with N = 10 and compare p = .2 to p = .5 for the accuracy of the probability of various outcomes.
true
.5
false
.8
Use the simulation with N = 10 and compare p = .8 to p = .5 for the accuracy of the probability of various outcomes.
The normal approximation to the binomial is most accurate for which of the following sample sizes?

The binomial distribution approaches a normal distribution as the sample size increases. Therefore the approximation is best when the sample size is highest.
false
4
Use the simulation with N = 10 and p = .5 to find the accuracy of the probability of various sample sizes.
false
8
Use the simulation with N = 10 and p = .5 to find the accuracy of the probability of various sample sizes.
true
12