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1695814
11-01-2002, 12:53 PM
Is there a way on the BA-35 to quickly/easily enter something like the table below to find out what the sample mean & variance are?

n number of policies with n claims
0 20
1 10
2 5
3 1

ok thanks.

Pi Man
11-01-2002, 01:31 PM
i have the ba-35 solar....

MODE until "STAT" displays

20 [sigma+] 10 [sigma+] 5 [sigma+] 1 [sigma+]

[2nd] [+/-] (it says "MEAN" which is x-bar, not "angry") :)

[2nd] [+] will give you sample std dev (square to get var)

[2nd] [=] will give you empir std dev (ditto)

if you calc the data mean and std dev, but remembered that you didn't add all the data, you can keep entering.... ( 22 [sigma+] ) and the new data is appended to the existing data....

hope this helps :D

Dr T Non-Fan
11-01-2002, 03:11 PM
For four data points, do it the long way.
Another idea: add X^2 and Y^2 columns right in the booklet. And any other columns that might be needed to make variances easier to calculate.

Pi Man
11-01-2002, 03:52 PM
oops - thought "n" was an index....

based on your example, it doesn't soundlike "n" is the number of datapoints, either. would the following be a similar example?

x y
5 11
8 16
10 22

although i've never seen an algorithm to find a "mean" value by summing the products of x and y.... it looks like you are looking for an expected value function, but then one of your data points would need to sum to unity....

am i missing something here? :-?

Gandalf
11-01-2002, 03:57 PM
1965814 was saying there were 36 observations. Of those, 20 observations were 0, 10 were 1, 5 were 2, 1 was 3. What is the sample mean and sample variance for those observations?

Pi Man
11-01-2002, 04:44 PM
:oops:
oh yeah; see that now.....

0 [sigma+] (20x) 1 [sigma+] (10x).....

the TI 30Xa has an "n" key where you can specify frequency (enter '20' instead of pressing [sigma+] 20 times......

does this help???? :)

thing
11-01-2002, 06:55 PM
Get the TI-30X.

Pi Man
11-02-2002, 12:43 PM
:Dcan't go wrong at that price!