What is the average of the first five multiples of 3____________?
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Answer: B. 9
Explanation
The first five multiples of 3 are 3, 6, 9, 12, and 15 respectively. The average of any arithmetic sequence with an odd count is the exact middle number. The middle number in the sequence of five multiples is 9. Multiples of a number are produced by multiplying that number by sequential integers. Arithmetic sequences feature a constant common difference between consecutive terms. Average equals the sum of all terms divided by the total count of terms.
Sequence analysis is foundational in number theory and arithmetic progression studies. Finding averages of sequential data points is common in statistical sampling. Quick mental math shortcuts rely on recognizing symmetry in arithmetic progressions. Choosing 3 represents only the first term in the sequence rather than the average. Choosing 12 represents the fourth term rather than the central average. Choosing 15 represents the final maximum term in the five multiple sequence.
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- Mathematics
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