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Finding the Fourth Proportional to 508.80, 702.40 and 312.64

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Solution

The fourth proportional to 508.80, 702.40 and 312.64 is: 431.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    508.80 : 702.40 = 312.64 : x
  2. Step 2: Convert to fraction form
    508.80/702.40 = 312.64/x
  3. Step 3: Cross multiply
    508.80x = 702.40 × 312.64
  4. Step 4: Simplify right side
    508.80x = 219,598.34
  5. Step 5: Solve for x
    x = 219,598.34/508.80
  6. Step 6: Final answer
    x = 431.60

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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.