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Finding the Fourth Proportional to 920.84, 1,378.38 and 486.68

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Solution

The fourth proportional to 920.84, 1,378.38 and 486.68 is: 728.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    920.84 : 1,378.38 = 486.68 : x
  2. Step 2: Convert to fraction form
    920.84/1,378.38 = 486.68/x
  3. Step 3: Cross multiply
    920.84x = 1,378.38 × 486.68
  4. Step 4: Simplify right side
    920.84x = 670,829.98
  5. Step 5: Solve for x
    x = 670,829.98/920.84
  6. Step 6: Final answer
    x = 728.50

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Double scale
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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.