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Finding the Fourth Proportional to 639.30, 957.60 and 570.90

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Solution

The fourth proportional to 639.30, 957.60 and 570.90 is: 855.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.30 : 957.60 = 570.90 : x
  2. Step 2: Convert to fraction form
    639.30/957.60 = 570.90/x
  3. Step 3: Cross multiply
    639.30x = 957.60 × 570.90
  4. Step 4: Simplify right side
    639.30x = 546,693.84
  5. Step 5: Solve for x
    x = 546,693.84/639.30
  6. Step 6: Final answer
    x = 855.14

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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.