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Finding the Fourth Proportional to 909.40, 1,255.02 and 511.20

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Solution

The fourth proportional to 909.40, 1,255.02 and 511.20 is: 705.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.40 : 1,255.02 = 511.20 : x
  2. Step 2: Convert to fraction form
    909.40/1,255.02 = 511.20/x
  3. Step 3: Cross multiply
    909.40x = 1,255.02 × 511.20
  4. Step 4: Simplify right side
    909.40x = 641,566.22
  5. Step 5: Solve for x
    x = 641,566.22/909.40
  6. Step 6: Final answer
    x = 705.48

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Double scale
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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.