# Mean??

• Oct 14th 2008, 06:10 PM
makaveli89
Mean??
(1 pt) The distribution below shows the number of dogs per family in the United States.
Number of Dogs Proportion of Families
0 0.505
1 0.203
2 0.191
3 0.073
4 0.028
Using the corresponding strings of Random digits, simulate a sampling of 10 U.S. families and calculate the Mean Number of dogs in the sample.

(a) 08422 68953 19645 09303 23209 02560
Mean of the Sample:

(b) 99019 02529 09376 70715 38311 31165
Mean of the Sample:

how can i calculate the mean??
• Oct 14th 2008, 09:35 PM
mr fantastic
Quote:

Originally Posted by makaveli89
(1 pt) The distribution below shows the number of dogs per family in the United States.
Number of Dogs Proportion of Families
0 0.505
1 0.203
2 0.191
3 0.073
4 0.028
Using the corresponding strings of Random digits, simulate a sampling of 10 U.S. families and calculate the Mean Number of dogs in the sample.

(a) 08422 68953 19645 09303 23209 02560
Mean of the Sample:

(b) 99019 02529 09376 70715 38311 31165
Mean of the Sample:

how can i calculate the mean??

Mean = $\sum_{i = 1}^{5} x_i \, p_i$ where $x_i$ is the number of dogs and $p_i$ is the proportion of families with $x_i$ dogs.
• Oct 14th 2008, 10:57 PM
makaveli89
so what about the string random digits 08422 68953 19645 09303 23209 02560. what do they signify?
• Oct 15th 2008, 12:40 AM
CaptainBlack
Quote:

Originally Posted by makaveli89
(1 pt) The distribution below shows the number of dogs per family in the United States.
Number of Dogs Proportion of Families
0 0.505
1 0.203
2 0.191
3 0.073
4 0.028
Using the corresponding strings of Random digits, simulate a sampling of 10 U.S. families and calculate the Mean Number of dogs in the sample.

(a) 08422 68953 19645 09303 23209 02560
Mean of the Sample:

(b) 99019 02529 09376 70715 38311 31165
Mean of the Sample:

how can i calculate the mean??

You take blocks of three random digits and treat as a three digit random number in the range 0,1. Then use this to generate the number of dogs in a hypothetical family.

The cumulative probability for the dog distribution is given below in the third cloumn, this is what you need to simulate a number of families dog ownership statistics:

0 0.505 0.505
1 0.203 0.708
2 0.191 0.899
3 0.073 0.978
4 0.028 1.000

So our first random number is 0.0842 this is less than 0.505 so this family has 0 dogs.

The next random number is 0.226, again less than 0.595 so the second familly has 0 dogs

The next random number is 0.895, again less than 0.899 but greater than 0.708 so the second familly has 2 dogs

etc

This gives you a sample of family dog ownership statistics from which you should compute a mean.

CB