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Finding the Fourth Proportional to 711.75, 981.50 and 641.91

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Solution

The fourth proportional to 711.75, 981.50 and 641.91 is: 885.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.75 : 981.50 = 641.91 : x
  2. Step 2: Convert to fraction form
    711.75/981.50 = 641.91/x
  3. Step 3: Cross multiply
    711.75x = 981.50 × 641.91
  4. Step 4: Simplify right side
    711.75x = 630,031.46
  5. Step 5: Solve for x
    x = 630,031.46/711.75
  6. Step 6: Final answer
    x = 885.19

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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.