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Group Exercise: More Standard Scores

Mon, 03/19/2018 - 15:10 — Professor Shortell

Suppose you are studying college graduates in the US. You know that the population mean student loan debt is $34,500 and the population standard deviation is $22,800.

You can compute the area under the normal curve here: http://www.stat.berkeley.edu/~stark/SticiGui/Text/clt.htm#normal_curve

What is the probability of selecting a college graduate at random:

  1. With a debt greater than $50,000?
  2. With a debt less than $10,000?
  3. With a debt greater than $30,000 but less than $40,000?
  4. With a debt greater than $15,000 but less than $25,000?
  5. With a debt greater than $55,000 but less than $75,000?

Comments

Mon, 03/19/2018 - 15:44 — GREGORY U

> 10000-34500
[1] -24500
> -24500/22800
[1] -1.074561

Z=-1.07

Mon, 03/19/2018 - 15:45 — ANNA W

z= (55,000-34,500)/22,800
z=.899

z= (75,000-34,500)/22,800
z=1.776

Mon, 03/19/2018 - 15:45 — ELISA N

Pop. mean = 34,500
Pop. sd = 22,800

50000-34500/22800

z= 0.6798

24.83%

Mon, 03/19/2018 - 15:47 — BRENDA R

3. z=.197
z=.241
Percentage: 17.33%

Mon, 03/19/2018 - 15:58 — AHMED D

standard deviation is $22,800.
Mean:$15,000 but less than $25,000
Z1=-0.85
Z2=-0.41

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