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Finding the Fourth Proportional to 978.34, 1,467.49 and 430.20

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Solution

The fourth proportional to 978.34, 1,467.49 and 430.20 is: 645.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.34 : 1,467.49 = 430.20 : x
  2. Step 2: Convert to fraction form
    978.34/1,467.49 = 430.20/x
  3. Step 3: Cross multiply
    978.34x = 1,467.49 × 430.20
  4. Step 4: Simplify right side
    978.34x = 631,305.79
  5. Step 5: Solve for x
    x = 631,305.79/978.34
  6. Step 6: Final answer
    x = 645.28

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.