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Finding the Fourth Proportional to 687.22, 947.37 and 424.78

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Solution

The fourth proportional to 687.22, 947.37 and 424.78 is: 585.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.22 : 947.37 = 424.78 : x
  2. Step 2: Convert to fraction form
    687.22/947.37 = 424.78/x
  3. Step 3: Cross multiply
    687.22x = 947.37 × 424.78
  4. Step 4: Simplify right side
    687.22x = 402,423.83
  5. Step 5: Solve for x
    x = 402,423.83/687.22
  6. Step 6: Final answer
    x = 585.58

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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.