Algebra-1

Question Analysis
This question involves finding the combined frequency of two categories ("13 or 15") from a frequency table.
The main focus is on summing the frequencies of specific categories to find a total for a grouped condition.

Key Concept Explanation
Combined Frequency: The sum of frequencies of two or more categories, representing the total number of observations that fall into any of those categories.

Step-by-Step Solution
Identify the frequencies of the target categories:
Frequency of 13-year-olds: 7.
Frequency of 15-year-olds: 8.
Sum the frequencies: 7 + 8 = 15.
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