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Finding the Fourth Proportional to 669.89, 924.51 and 421.40

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Solution

The fourth proportional to 669.89, 924.51 and 421.40 is: 581.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.89 : 924.51 = 421.40 : x
  2. Step 2: Convert to fraction form
    669.89/924.51 = 421.40/x
  3. Step 3: Cross multiply
    669.89x = 924.51 × 421.40
  4. Step 4: Simplify right side
    669.89x = 389,583.89
  5. Step 5: Solve for x
    x = 389,583.89/669.89
  6. Step 6: Final answer
    x = 581.57

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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.