any1 know statistics??

[doubles1]

The following frequency table summarizes the ages of 64 shoppers at the local grocery store.

Ages 15 – 23
Frequency
10

Ages
24 – 32
Frequency
21

Ages
33 – 41
Frequency
10

Ages
42 – 50
Frequency
8

Ages
51 – 59
Frequency
5

Ages
60 – 68
Frequency
6

The sample mean for the above frequency table is calculated as 36.25. Calculate the (approximate) sample variance and standard deviation for this data set.

I WILL GIVE AS MUCH KARMA TO THE ANSWER HELPER!

 

[Raptorex]

 

[nycgirl]

Dude, use Excel to figure this out.

 

[doubles1]

i have been using excel...however i do not know how to for this problem.

any help would be greatly appreciated...

thanks

 

[nycgirl]

Okay, give me a minute.

 

[nycgirl]

Hey, that doesn't add up to 64. Are those the right numbers?

Here are the formulas:
The formula for Variance = s2 = (Xi - mean)2 + (Xi - mean)2 . . . . / n-1

Std. Dev. (S) = The square root of s2

Learn how to use Excel.

 

[doubles1]

HEY NYC!!!!

it is for 60 shoppers...sorry...it wasa misprint...i am trying to learn excel however i need to have this done in 45 mins !!!!

 

[nycgirl]

HEY NYC!!!!

it is for 60 shoppers...sorry...it wasa misprint...i am trying to learn excel however i need to have this done in 45 mins !!!!

I gave you the formulas. Its pretty easy.

Okay, Variance = 33.2

Standard Dev. = 5.76

Mean = 10

(10-10)2 + (21-10)2 + (10-10)2 + (8-10)2 + (5-10)2 + (6-10)2 / 6-1 = 33.2 (Variance)

Square Root of 33.2 = 5.76 (Std. Dev.)

 

[Raptorex]

but what is the third and first moment misses smarty pants.

I gave you the formulas. Its pretty easy.

Okay, Variance = 33.2

Standard Dev. = 5.76

Mean = 10

(10-10)2 + (21-10)2 + (10-10)2 + (8-10)2 + (5-10)2 + (6-10)2 / 6-1 = 33.2 (Variance)

Square Root of 33.2 = 5.76 (Std. Dev.)

 

[biteme]

Statistics was a relatively easy class for me. Even though I made an A in trig, that class stressed the heck out of me. I would dream those formulas in my sleep.