Comparing Central Tendency & Variability

About: At what age do people have their first child? While it may seem like a personal choice, there are sociological trends in the age at which people have their first child.

In this lab analysis report, we will be using real data to examine the question: At what age do people in the United States have their first child?

Warning: We will be applying the concepts of central tendency and variability in this lab. If you have not read and taken notes on our chapters 3 & 4 and lecture videos make sure to do so before starting this assignment.

Background & Results:

These results come from a national survey called the General Social Survey. They provide us with an insight on American habits and behaviors. People from across the U.S. of all backgrounds, ages, social class, and genders were asked several questions including the following question: How old were you when your first child was born?

Here are the results!

Table 1: Statistics for Variable: Age You Had Your First Child



(Sample Size)

Mean Median Mode Range IQR S.D.
Age Respondent Had Their First Child


24.9 years

24 years

21 years

13 to 52 years

20 to 29 years

6.1 years


For your original post in paragraph format write a minimum of 200 words and provide answers and statements to the following prompts:

  • (Make sure to answer the questions in paragraph format)
  • Examine the results for central tendency and interpret the findings. On average, when did people have their first child? Use the mean, median, and the mode to answer this question
    • Interpret the findings for each the mode, median, and the mean
  • Examine the results for measures of variability and interpret the findings. How much variation did Americans have in terms of their age when they had their first child? Use the range, IQR, and standard deviation to answer these questions
    • Interpret the findings for each the range, IQR, and standard deviation
  • (OPTIONAL) When did your parents have their first child? Are they above or below the national average?
  • Is there much variability in the among Americans as to what age they have their first child? Does it vary widely from person to person or is there consistency in everyone’s answer? Make conclusions and discuss the variability found in the results. What measures provide us evidence to support your conclusions?
  • Lastly, what additional variables can influence the variable: age at which respondent had their first child?