Question

For a group experiment, your science class measured the fine-particulate concentrations in the air at random places around campus, and estimated a sample average of 22 μg/m3 (micrograms per cubic meter). If 144 readings were taken, and the standard deviation of the sample measurements was 4 μg/m3, you are 99.7% confident that actual concentration of fine particulates at the school is __________ .

a=21.3μg/m3 -22.7μg/m3
b=21μg/m3- 23μg/m3
c=18μg/m3-26μg/m3
d=21.7μg/m3-22.3μg/m3

Answer 1

@ash2326

Answer 2

@tkhunny

Answer 3

Please show your work. You need a 99.7% z-score and you're almost done.

Answer 4

thats the thing i just copied and pasted the question. i never took stats a day in my life

Answer 5

Awesome. Why do you have this problem?

If you are not prepared for it, why were you given it?

Is this a placement exam? If it is, you should miss this one so that you will be placed in the correct class.

Answer 6

no my little sister has summer school and my parents asked me to finish it for her. i got the stats section and trig section left. i no trig just never learned stats

Answer 7

@dumbcow @jim_thompson5910

Answer 8

that makes no sense ... why would your parents ask you to do your sisters homework when you never even were in the same class ??

Answer 9

bc i graduated alrdy?

Answer 10

yet you never learned stats?

Answer 11

nope

Answer 12

if i did i wouldnt be here XD

Answer 13

wouldn't your parents know you never took stats, so why ask you to help ??
have your sister do her own work

Answer 14

its algebra II one of the sectons is on statistics. and yea that what ive been saying but "she just doesnt get it"

Answer 15

so the blind helping the blind apparently

Answer 16

on this section yes. i know the other 11 sections......

Answer 17

anyway answer is B

std err = std dev/ sqrt(n)

confidence interval = mean +- 3*std err

Answer 18

thanks!
i apreciate it

Answer 19

yw

Answer 20

and dnt think i want to be here doing it lol ive been doing it for the past 3 days