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Finding the Fourth Proportional to 840.38, 1,260.50 and 320.15

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Solution

The fourth proportional to 840.38, 1,260.50 and 320.15 is: 480.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.38 : 1,260.50 = 320.15 : x
  2. Step 2: Convert to fraction form
    840.38/1,260.50 = 320.15/x
  3. Step 3: Cross multiply
    840.38x = 1,260.50 × 320.15
  4. Step 4: Simplify right side
    840.38x = 403,550.63
  5. Step 5: Solve for x
    x = 403,550.63/840.38
  6. Step 6: Final answer
    x = 480.20

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1.5x scale

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.