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Finding the Fourth Proportional to 912.90, 1,259.76 and 519.90

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Solution

The fourth proportional to 912.90, 1,259.76 and 519.90 is: 717.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.90 : 1,259.76 = 519.90 : x
  2. Step 2: Convert to fraction form
    912.90/1,259.76 = 519.90/x
  3. Step 3: Cross multiply
    912.90x = 1,259.76 × 519.90
  4. Step 4: Simplify right side
    912.90x = 654,949.22
  5. Step 5: Solve for x
    x = 654,949.22/912.90
  6. Step 6: Final answer
    x = 717.44

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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.