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Finding the Fourth Proportional to 520.90, 718.40 and 421.27

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Solution

The fourth proportional to 520.90, 718.40 and 421.27 is: 581.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.90 : 718.40 = 421.27 : x
  2. Step 2: Convert to fraction form
    520.90/718.40 = 421.27/x
  3. Step 3: Cross multiply
    520.90x = 718.40 × 421.27
  4. Step 4: Simplify right side
    520.90x = 302,639.63
  5. Step 5: Solve for x
    x = 302,639.63/520.90
  6. Step 6: Final answer
    x = 581.00

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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.