Investigations into Mathematics: Survey Project Number of Siblings Daniel Ballew October 8, 2010

Introduction I surveyed 6 th, 7 th, and 8 th graders to find out how many siblings they have. I asked an equal number of people from each grade and an equal number of boys and girls.

Surveying Technique I surveyed 24 people for my survey. My sampling technique was stratified random sample. It is stratified because I divided the population of JPMS students into groups of boys and girls by grade. It is unbiased because I got an equal number of responses from each of the 3 grades at JPMS and an equal number of boys and girls. Participants were chosen at random.

Data

Best Representation Mean Samples = 24 Mean = Median = 1 Mode = 1 Range = 3

Analysis of Data The mean is the best measure of central tendency that describes this set of data. There are no outliers. The distribution of data is not skewed. The mean (1.375) falls between the mode (1) and the next most probable value (2). I know it can’t be mode because the number of ones and twos are too close together in number. That is why I chose mean.

Misleading Graph Exaggerates differences with Y- axis offset. Scale is unusual

Analysis by Grade 7 th graders tend to have more siblings than 6 th and 8 th graders.

Boys vs. Girls The distribution for boys is skewed to higher numbers of siblings, but 2 girls had the largest number of siblings.

Conclusions The average JPMS student has siblings. If you ask any girl, she is most likely to answer, “one.” If you ask any boy, he is almost equally likely to answer, “two” or “one.”