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Finding the Fourth Proportional to 687.52, 948.80 and 491.50

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Solution

The fourth proportional to 687.52, 948.80 and 491.50 is: 678.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.52 : 948.80 = 491.50 : x
  2. Step 2: Convert to fraction form
    687.52/948.80 = 491.50/x
  3. Step 3: Cross multiply
    687.52x = 948.80 × 491.50
  4. Step 4: Simplify right side
    687.52x = 466,328.00
  5. Step 5: Solve for x
    x = 466,328.00/687.52
  6. Step 6: Final answer
    x = 678.28

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.