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Finding the Fourth Proportional to 500.79, 691.32 and 420.99

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Solution

The fourth proportional to 500.79, 691.32 and 420.99 is: 581.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    500.79 : 691.32 = 420.99 : x
  2. Step 2: Convert to fraction form
    500.79/691.32 = 420.99/x
  3. Step 3: Cross multiply
    500.79x = 691.32 × 420.99
  4. Step 4: Simplify right side
    500.79x = 291,038.81
  5. Step 5: Solve for x
    x = 291,038.81/500.79
  6. Step 6: Final answer
    x = 581.16

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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.