2. A researcher measures the heart rate in a population of runners and finds they have an average heart rate of µ = 50, σ = 5. You do not need to show a graph, only computation work.

Question

2A. Based on the average heart rate cited above, what proportion would we expect to have a heart rate of 55 or more? Show your Work! (2 points)

2B. Based on the average heart rate cited above, what proportion would we expect to have a heart rate of 40 or less? Show your Work! (2 points)

2C. Based on the average heart rate cited above, what proportion would we expect to have a heart rate between 55 and 65? Show your Work! (3 points)

2D. Based on the average heart rate cited above, what heart rate would we expect to cut off the top 10% of the distribution? Show your Work! (2 points)

3. A group of toys consists of the following:

5 dolls
7 stuffed animals
3 toy guns

3A. If I choose at random from the group of toys, what is the probability I get a doll--P(doll)?
Show your Work! (2 points)
1/3

3B. If I choose at random from the group of toys, what is the probability I get a doll or a gun--P(doll or gun)? Show your Work! (2 points)

3C. If I choose two toys at random (with replacement), what is the probability I get a doll and a stuffed animal—P (doll and stuffed animal)? Show your Work! (2 points)

3D. If take out toys and give them away as I take them (without replacement), what is the probability I get a doll, a stuffed animal, and a gun—P(doll and stuffed animal and gun)?
Show your Work! (2 points)

Answer 1

for 2 use :

http://davidmlane.com/hyperstat/z_table.html

Answer 2

3 a

Yes, 5/15 = 1/3

3 b
just add 5/15 + 3/15 = 8/15

3 c
p
what are chances of
d then a then g ?
5/15 * 7/14 * 3/13 = .03846153
d then g then a ?
5/15 * 3/14 * 7/13 = same
etc
a then d then g
a then g then d
g then d then a
g then a then d

six ways in total, each .03846153
so multiply by 6 and get
.231