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Finding the Fourth Proportional to 752.90, 1,038.90 and 421.34

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Solution

The fourth proportional to 752.90, 1,038.90 and 421.34 is: 581.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    752.90 : 1,038.90 = 421.34 : x
  2. Step 2: Convert to fraction form
    752.90/1,038.90 = 421.34/x
  3. Step 3: Cross multiply
    752.90x = 1,038.90 × 421.34
  4. Step 4: Simplify right side
    752.90x = 437,730.13
  5. Step 5: Solve for x
    x = 437,730.13/752.90
  6. Step 6: Final answer
    x = 581.39

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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.