Answer:
19.2
Step-by-step explanation:
You get the mean of a set of numbers by adding them and dividing the sum by how many numbers there are. In this case, you don't know what the individual 8 numbers are, but you can find out what they add up to.
Mean = (sum) / 8
17 = (sum) / 8
17 x 8 = sum
136 = sum
Now take out the numbers 9, 11, 20, which reduces the sum by 40. There are 5 numbers left and they add up to 136 - 40 = 96.
The new mean is 96 / 5 = 19.2
The answer would be 28 but couldnt you have done this yourself?
Answer:
-Convenience Sampling
Step-by-step explanation:
Convenience Sampling is a sampling method that is employed simply because the samples are easy to reach or access. It is a non-probability system of sampling and not a very strong method of sampling. For a serious research such as the one being conducted by the Superintendent, who has ample time to perform the research, this is not a very good sampling method. A Convenience style of research would mean that he can just walk into a cafeteria with students and administer the test to them.
Since he has detailed information of the students, he should choose any of the other mentioned sampling techniques in the options provided to randomly select the subjects. <em>This would help to</em> prevent bias, and enable him to make generalizations with the result of the research.
F(180) = x/30
= 180/30 = 6 gallons of gas is needed
To compare the two classes, the Coefficient of Variation (COV) can be used.
The formula for COV is this:
C = s / x
where s is the standard deviation and x is the mean
For the first class:
C1 = 10.2 / 75.5
C1 = 0.1351 (13.51%)
For the second class:
C2 = 22.5 / 75.5
C2 = 0.2980 (29.80%)
The COV is a test of homogeneity. Looking at the values, the first class has more students having a grade closer to the average than the second class.
