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Help me please answer is not A

Help me please answer is not A-example-1
User Neitsa
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5 votes

Answer:

B) 16.47

Explanation:

In order to find the mean of grouped data with intervals, we use the formula

(∑f * m) / (∑f)

  • where (∑f * m) is the sum of the product of each frequency (f) and the corresponding midpoint (m) for its interval and (∑f is the sum of each frequency

Step 1: First, we need to find the sum of the frequencies: ∑f = 2 + 3 + 8 + 4 = 17

Step 2: Next, we need to find the midpoint (m) of each interval. We do this by averaging the end points of each interval

m of first interval: (9.5 + 12.5) / 2 = 11

m of second interval: (12,5 + 15.5) / 2 = 14

m of third interval: (15.5 + 18.5) / 2 = 17

m of fourth interval: (18.5 + 21.5) / 2 = 20

Step 3: Now, we multiply the frequency for each interval by its corresponding midpoint and add them together to find the sum

f * m for first interval: (2 * 11) = 22

f * m for second interval: (3 * 14) = 42

f * m for third interval: (8 * 17) = 136

f * m for fourth interval: (4 * 20) = 80

Sum of f * m for each interval: 22 + 42 + 136 + 80 = 280

Step 4: Finally, we divide the sum of f * m for each interval by the sum of f to find the mean:

280 / 17 = 16.47058824 = 16.47

User IAhmed
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