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Finding the Fourth Proportional to 909.79, 1,255.41 and 511.38

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Solution

The fourth proportional to 909.79, 1,255.41 and 511.38 is: 705.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    909.79 : 1,255.41 = 511.38 : x
  2. Step 2: Convert to fraction form
    909.79/1,255.41 = 511.38/x
  3. Step 3: Cross multiply
    909.79x = 1,255.41 × 511.38
  4. Step 4: Simplify right side
    909.79x = 641,991.57
  5. Step 5: Solve for x
    x = 641,991.57/909.79
  6. Step 6: Final answer
    x = 705.65

Related Problems

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Double scale
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1.5x scale

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.