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Finding the Fourth Proportional to 898.76, 1,240.30 and 505.78

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Solution

The fourth proportional to 898.76, 1,240.30 and 505.78 is: 697.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    898.76 : 1,240.30 = 505.78 : x
  2. Step 2: Convert to fraction form
    898.76/1,240.30 = 505.78/x
  3. Step 3: Cross multiply
    898.76x = 1,240.30 × 505.78
  4. Step 4: Simplify right side
    898.76x = 627,318.93
  5. Step 5: Solve for x
    x = 627,318.93/898.76
  6. Step 6: Final answer
    x = 697.98

Related Problems

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Half scale
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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.