The parallel dot plots below represent the total family income of randomly selected individuals from Indiana (38 individuals) and New Jersey (44 individuals). Compare the income distributions for these two samples.

Mathematics · High School · Thu Feb 04 2021

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Answer: When comparing the income distributions for the two samples from Indiana and New Jersey using parallel dot plots, you should look at several factors: center (mean or median), spread (range, interquartile range, or standard deviation), shape of the distribution, and the presence of any outliers.

1. Center: Observe whether the dots are clustered more towards the higher or lower end in one state versus the other. You can estimate the median by finding the middle dot(s) in each plot, and the mean by gauging the balance point of the distribution.

2. Spread: Look at the range by identifying the lowest and highest dots for each state. A wider range indicates a larger spread of income. You can also assess the compactness of the dots to infer the concentration of the data points.

3. Shape: Describe any patterns you see, such as if the dots are skewed towards higher or lower incomes or if they are symmetrically distributed.

4. Outliers: Notice if there are dots that stand apart from the rest of the data, which could represent unusually low or high income for that state.

By comparing these elements, you can draw conclusions about the differences in income distribution between the two states. For example, you could say that one state has a higher median income if the middle dot is higher on that state's plot, or that the income is more varied in one state if the range is wider.

Extra: Comparing distributions using dot plots is a fundamental concept in descriptive statistics. Here's an overview of the concepts mentioned:

- Center: This is the middle of a data set. The mean (average) is one measure of the center, calculated by adding all the values and dividing by the number of values. The median is another measure, which is the middle value when all the observations are ordered from lowest to highest.

- Spread: This describes how far apart the data points are. Common measures of spread include the range (difference between the highest and lowest values), interquartile range (the range of the middle 50% of the data), and standard deviation (which quantifies the amount of variation or dispersion in a set of values).

- Shape: This refers to the outline formed by the data points on the plot. The shape can be described as symmetric, skewed (left or right), or uniform, among others. The shape can tell us about the distribution of data and whether it follows any known statistical distribution such as the normal distribution.

- Outliers: These are data points that are significantly different from the rest of the data. They can affect the mean and can sometimes indicate data entry errors, measurement errors, or that the individual is truly different from the rest of the sample.

Understanding these concepts helps in comparing data sets effectively and in drawing meaningful conclusions about them.