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Finding the Fourth Proportional to 928.48, 1,280.70 and 555.21

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Solution

The fourth proportional to 928.48, 1,280.70 and 555.21 is: 765.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.48 : 1,280.70 = 555.21 : x
  2. Step 2: Convert to fraction form
    928.48/1,280.70 = 555.21/x
  3. Step 3: Cross multiply
    928.48x = 1,280.70 × 555.21
  4. Step 4: Simplify right side
    928.48x = 711,057.45
  5. Step 5: Solve for x
    x = 711,057.45/928.48
  6. Step 6: Final answer
    x = 765.83

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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.