Describe the steps you would use to find the estimated mean of grouped data.?

Answer 1

I didn't take statistics. However, I think you would average a small sample of the data from random to find the estimated mean. If you used all of the data then it wouldn't be an estimate anymore.

1,4,3,5,6,7,2,3,8,3
Pick several numbers from random. More numbers = better estimate.
1,5,3,8 ... average those numbers = 4.25

Answer 2

First, find the average of each group. Just add the top and bottom numbers of the group range and divide by 2.

Second, assume every member of the group had that value and multiply the average from that group by the number of members of that group. Do this for all the groups and add all these numbers together.

Last, divide this number by the total number of data points.

What you are really taking is the average of the averages.

Think of it this way. If the range of the first group was from 8 to 12 and there were 15 members in the group, then pretend that you had 15 members all with a value of 10 (the average of the group).

Answer 3

Your data points are grouped into ranges, e.g. 0 - 4; 5 - 8; etc.
You will know how many you have in each grouping.
To find the estimated mean, you need to add the products of the number in each range multiplied by the average of each range; then divide the sum by the total number of data points.

range____number____ mean of range
0 - 4 ____ 12 ____ ____ (0+4)/2 = 2
5 -8 _____ 9 _____ ____ (5+8)/2 = 6.5
________ ----
________ 21

((12 * 2) + (9 * 6.5))/ 21 = 3.93


It's an estimated mean, since you are not calculating the mean using each data point

Answer 4

For each class, take the middle value of the class and use that as the estimated value for each observation in that class.

So if there are eight values between 5 and 10, then assume that there are eight 7.5's ({5+10}/2). If there are four values between 10 and 20, then assume that there are four 15's ({10+20}/2).

Then take the average of these values. That is the grouped mean, which as you said, estimates the actual sample mean.

Answer 5

I would simply add all of the data together and divide by how many sets of grouped data's there is. For example, take 5,17,29,56. You would add them together and get 107. Then divided by four(how many numbers there is) to get the mean of the numbers and find the answer to be 26.75.

Answer 6

summation fx/f is formula for calculating mean of groued data it means that u first add the marks up i mean x and then divide by frequency

Answer 7

the mean is given by the formula sigma f*x/sigma f where f is the frequency of each class interval,and x is the mid value of the class interval