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Finding the Fourth Proportional to 684.36, 1,031.58 and 648.72

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Solution

The fourth proportional to 684.36, 1,031.58 and 648.72 is: 977.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.36 : 1,031.58 = 648.72 : x
  2. Step 2: Convert to fraction form
    684.36/1,031.58 = 648.72/x
  3. Step 3: Cross multiply
    684.36x = 1,031.58 × 648.72
  4. Step 4: Simplify right side
    684.36x = 669,206.58
  5. Step 5: Solve for x
    x = 669,206.58/684.36
  6. Step 6: Final answer
    x = 977.86

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.