Inferential Statistics

random sampling

random assignment

random sampling

random assignment

include as many members of the population as possible in the research

obtain the largest possible sample

obtain a representative sample from which generalizations can be made

guarantee that the research sample will proportionally represent the population of interest

frequency

mean

mode

standard deviation

In a study of science performance among CPS high school students, the four-year science course grades of 300 graduating LPHS seniors are recorded.

In a study of science performance among CPS high school students, the four-year science course grades of 3,000 graduating seniors from various CPS schools in different neighborhoods are recorded.

The average science course grades of LPHS graduating seniors is higher for females than for males. Specifically, the average course grade for females was 83%, and for males it was 70%.

The average science course grades of LPHS graduating seniors is higher for females than for males. Specifically, the average course grade for females was 83%, and for males it was 81%.

The average science test grades of LPHS graduating seniors is higher for females than for males. The data also show a large number of extreme scores (outliers) in the female data set.

The average science test grades of LPHS graduating seniors is higher for females than for males. The data also show that scores are close to the mean for both groups.