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Finding the Fourth Proportional to 681.51, 1,017.15 and 665.10

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Solution

The fourth proportional to 681.51, 1,017.15 and 665.10 is: 992.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.51 : 1,017.15 = 665.10 : x
  2. Step 2: Convert to fraction form
    681.51/1,017.15 = 665.10/x
  3. Step 3: Cross multiply
    681.51x = 1,017.15 × 665.10
  4. Step 4: Simplify right side
    681.51x = 676,506.47
  5. Step 5: Solve for x
    x = 676,506.47/681.51
  6. Step 6: Final answer
    x = 992.66

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.