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Finding the Fourth Proportional to 937.79, 1,290.68 and 688.72

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Solution

The fourth proportional to 937.79, 1,290.68 and 688.72 is: 947.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    937.79 : 1,290.68 = 688.72 : x
  2. Step 2: Convert to fraction form
    937.79/1,290.68 = 688.72/x
  3. Step 3: Cross multiply
    937.79x = 1,290.68 × 688.72
  4. Step 4: Simplify right side
    937.79x = 888,910.68
  5. Step 5: Solve for x
    x = 888,910.68/937.79
  6. Step 6: Final answer
    x = 947.88

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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.