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Finding the Fourth Proportional to 565.90, 781.40 and 420.10

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Solution

The fourth proportional to 565.90, 781.40 and 420.10 is: 580.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    565.90 : 781.40 = 420.10 : x
  2. Step 2: Convert to fraction form
    565.90/781.40 = 420.10/x
  3. Step 3: Cross multiply
    565.90x = 781.40 × 420.10
  4. Step 4: Simplify right side
    565.90x = 328,266.14
  5. Step 5: Solve for x
    x = 328,266.14/565.90
  6. Step 6: Final answer
    x = 580.08

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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.