Math Problem Statement

(b)Find the third quartile of the scores.

The third quartile of the scores is 

Solution

To find the third quartile (Q3) of the scores, you can follow a similar process to that used for finding the first quartile:

  1. Determine the position of the third quartile (Q3):

    • The third quartile (Q3) is the 75th percentile of the data.
    • The formula to find the position PP of Q3 in an ordered data set is: P=3(n+1)4P = \frac{3(n+1)}{4} where nn is the number of data points.
  2. Calculate the position:

    • Here, n=29n = 29.
    • So, P=3(29+1)4=904=22.5P = \frac{3(29+1)}{4} = \frac{90}{4} = 22.5.
  3. Interpret the position:

    • Since 22.5 is not an integer, the third quartile will be the average of the 22nd and 23rd data points.
  4. Find the 22nd and 23rd data points:

    • The 22nd data point is 88, and the 23rd data point is 90.
  5. Calculate Q3: Q3=88+902=1782=89Q3 = \frac{88 + 90}{2} = \frac{178}{2} = 89

Thus, the third quartile (Q3) of the scores is 89.

Would you like more details or have any questions? Here are some related questions to expand your understanding:

  1. How does the third quartile compare to the mean of this data set?
  2. How do you determine if a data set is skewed based on its quartiles?
  3. What are the implications of a higher third quartile in a data set?
  4. How can you use Q3 to identify outliers in this data set?
  5. How would the quartiles change if a new score, say 100, was added to the data set?

Tip: Quartiles are key in identifying the spread and central tendency of data. Q3 is particularly useful in understanding the upper spread of the data set.

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Math Problem Analysis

Mathematical Concepts

Statistics
Percentiles
Quartiles

Formulas

Position of quartiles in an ordered data set

Theorems

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Suitable Grade Level

High School