This is an averages question testing the sum method. Choice C (92) is correct — current total sum = 4 × 82 = 328. Required total sum for a new average of 84 over 5 tests = 5 × 84 = 420. Required 5th score = 420 − 328 = 92. Choice A (86) comes from simply adding 2 to the target average of 84 — an intuitive but incorrect shortcut that ignores how averages compound across multiple values. Choice B (90) is a guess midway between 84 and 94, with no calculation behind it. Choice D (94) may result from computing 82 + (5 × (84 − 82)) = 82 + 10 = 92... actually 94 could come from 82 + 2 × 6 = 94 — an incorrect scaling. Pro tip: The sum method never fails for average problems — (target average × new count) − (current average × current count) = the missing value. The missing score must be ABOVE the new average to pull the mean up.

The median is the middle value when data is sorted in order. First, sort the data: [10, 12, 14, 16, 18]. Since there are 5 values (odd count), the median is the middle (3rd) value $= 14$. The median provides a measure of central tendency that is not affected by extreme values.

The median is the middle value when data is sorted in order. First, sort the data: [5, 7, 8, 9, 12]. Since there are 5 values (odd count), the median is the middle (3rd) value = 8. The median is resistant to extreme values and represents the central tendency.

The mode is the value that appears most frequently in the dataset. Counting frequencies: 7 appears 2 times, 9 appears 3 times, 5 appears 1 time. Since 9 appears most frequently (3 times), the mode is 9. Choice B gave 7, which appears only twice.

The mean is calculated by finding the sum of all values and dividing by the count. Sum = 3 + 7 + 5 + 10 + 8 = 33. Count = 5 values. Mean = 33 ÷ 5 = 6.6. Choice B gave 7, which would be incorrect arithmetic.

The range is calculated as the difference between the maximum and minimum values. First, identify the maximum value (33) and minimum value (14). Range = maximum - minimum = 33 - 14 = 19. The range provides a simple measure of how spread out the data values are.

The median is the middle value when data is sorted in order. First, sort the data: [5, 7, 9, 13, 15]. Since there are 5 values (odd count), the median is the middle (3rd) value $= 9$. The median divides the dataset into two equal halves.

The mode is the value that appears most frequently in the dataset. Counting frequencies: 3 appears 3 times, 8 appears 1 time, 5 appears 1 time, 9 appears 1 time, 2 appears 1 time. Since 3 appears most frequently, the mode is 3.

The range is calculated as the difference between the maximum and minimum values. First, identify the maximum value (25) and minimum value (11). Range = maximum - minimum = 25 - 11 = 14. The range indicates the total span of values from the smallest to the largest data point.

The median is the middle value when data is sorted in order. First, sort the data: [22, 23, 28, 29, 34]. Since there are 5 values (odd count), the median is the middle (3rd) value = 28. The median represents the value that divides the ordered dataset in half.