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Finding the Fourth Proportional to 421.32, 580.80 and 290.64

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Solution

The fourth proportional to 421.32, 580.80 and 290.64 is: 400.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.32 : 580.80 = 290.64 : x
  2. Step 2: Convert to fraction form
    421.32/580.80 = 290.64/x
  3. Step 3: Cross multiply
    421.32x = 580.80 × 290.64
  4. Step 4: Simplify right side
    421.32x = 168,803.71
  5. Step 5: Solve for x
    x = 168,803.71/421.32
  6. Step 6: Final answer
    x = 400.65

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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.