Question

Standard Deviation in statistics!!! please help:)

The mean for stats test scores is 63 and the standard deviation is 6.0. For the bio test scores, the mean is 24 and the standard deviation is 3.8. The test scores of a student who took both tests are given below.
A student gets a 76 on the stats test and a 29 on the bio test.

a) Transform each test score into a z-score
b) Determine on which test the student had a better score

Answer 1

@jim_thompson5910 :D

Answer 2

@satellite73

Answer 3

hint:

z = (x - mu)/sigma

Answer 4

mu = mean
sigma = standard deviation

Answer 5

x is the raw score
z is the z-score

Answer 6

so I got z=2 for the stats test

Answer 7

Not sure if that's off since it says round to the nearest hundredth

Answer 8

Nvm got 2.16 and 1.32

Answer 9

stats test

z = (x - mu)/sigma

z = (76 - 63)/6

z = 2.1667

Answer 10

So it would be 2.17 rounded to the nearest hundredth

Answer 11

1.32 is correct for the bio test

Answer 12

Thank you, you're the only person who helps with my new stats questions:) Much appreciated

Answer 13

sure thing

Answer 14

@jim_thompson5910 one question

Answer 15

If the mean life of a tire is 32,000 miles, and a standard deviation of 2150, then 37000 would be unusual?

Answer 16

what's the z score here

Answer 17

2.33

Answer 18

Since P[Z>2.33] = 0.00990308, I'd say it's very unlikely to happen which means it's pretty unusual. Basically this score and any score above 2.33 is somewhat rare to occur.

http://www.wolframalpha.com/input/?i=P%5BZ%3E2.33%5D