I'm in a crunch someone help me quick

Question

kkutie7 · Answer

how do you calculated the pooled standard deviation?

kainui · Answer

@nincompoop

kkutie7 · Answer

i need it at a certain confidence level i need to know if my two sets are significantly different. I could post the set but I'd must rather not.

brainzonly · Answer

The pooled standard deviation is a method for estimating a single standard deviation to represent all independent samples or groups in your study when they are assumed to have a common standard deviation. The pooled standard deviation is the average spread of all data points about their group mean (not the overall mean). It is a weighted average of each group's standard deviation. The weighting gives larger groups a proportionally greater effect on the overall estimate.

brainzonly · Answer

Suppose C1 contains the response, and C3 contains the mean for each factor level. For example:

brainzonly · Answer

Use the Calculator with the following expression: 

SQRT((SUM((C1 - C3)^2)) / (total number of observations - number of groups)

brainzonly · Answer

In other words, add up all of the #s in C1 and C2 (separately! then insert square root function in your calculator and then the difference of the sum of C1 and the sum of C2 squared and push enter.

brainzonly · Answer

(the table was just an example. Use it on your own table! :)   )

kkutie7 · Answer

alright so this doesn't help me at all really I have measured ten of two types of beans by weight:
pinto beans (mg):       navy beans (mg):
403.7                         191.4
322.1                         193.2
393.5                         258.6
370.3                         201.1
354.6                         180.8
360.8                         211.2
372.8                         178.5
405.6                         248.3
372.8                         227.1
332.7                         180.4

kkutie7 · Answer

I'm supposed to calculate the pooled standard deviation and determine if the two sets are significantly different at the 90% confidence level.

brainzonly · Answer

Add all of the pinto beans up. write the number down.
Add all of the navy beans up. write the number down.
Now, find the square root function on your calculator. Push it. Then, type in a left parentheses followed by the number of pinto beans, subtraction sign, number of navy beans, right parentheses. Now, find the exponent function and put in an exponent of 2. push enter. that's your answer. If you still don't understand, then I will just have to tell you the answer.