Question

The adult men of the Dinaric Alps have the highest avg. height of all regions. Mean is 73 in, standard deviation is 3in. Find the 40th percentile of the height of Dinaric Alps distribution for men?

Answer 1

@jim_thompson5910

Answer 2

@TheSmartOne

Answer 3

@AlexandervonHumboldt2

Answer 4

Please help, I have a lot of questions like these.

Answer 5

are you allowed to use a calculator? or table?

Answer 6

yup

Answer 7

what kind of calc do you have?

Answer 8

ti-84

Answer 9

ok hit 2nd, then the vars key

go to invNorm

Answer 10

kk

Answer 11

you will type in

invNorm(0.40)

to get the z-score

Answer 12

tell me what you get

Answer 13

area is .4?

Answer 14

But I got 72.24

Answer 15

what did you type in to get 72.24?

Answer 16

yes the area is 0.4

Answer 17

I just hit the invnorm and put in .4, 73, and 3.

Answer 18

that works

Answer 19

So is that the answer??

Answer 20

another way is to do it without 73 and 3

then use the formula z = (x-mu)/sigma

Answer 21

yes it is

Answer 22

what is m?

Answer 23

Oh cool thanks. So what does the percentile mean?

Answer 24

40th percentile means 40% of the population is below this score

they often state percentiles on tests like the SAT, ACT, etc. If you score in say the 90th percentile, then you scored higher than 90% of the students

Answer 25

Ohhh okay thank you. So what I'm doing is finding the value at which that is true?

Answer 26

yeah you're finding that score where 40% of the population is below this score

Answer 27

Ok thanks a ton! And one more question with the same info, what percentage of men have a height between 70in and 78in?

Answer 28

I just find the z value associated with 78 and subtract it with the z value of 70, correct?

Answer 29

so you'll type in

normalcdf(70,78,73,3)

assuming the mean is 73, SD is 3

Answer 30

Okay, and the minimum height to place someone in the top 10% that would just be the 90th percentile?

Answer 31

correct

Answer 32

Thank you so much for all your help!!

Answer 33

np