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Finding the Fourth Proportional to 687.39, 949.07 and 491.47

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Solution

The fourth proportional to 687.39, 949.07 and 491.47 is: 678.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.39 : 949.07 = 491.47 : x
  2. Step 2: Convert to fraction form
    687.39/949.07 = 491.47/x
  3. Step 3: Cross multiply
    687.39x = 949.07 × 491.47
  4. Step 4: Simplify right side
    687.39x = 466,435.52
  5. Step 5: Solve for x
    x = 466,435.52/687.39
  6. Step 6: Final answer
    x = 678.56

Related Problems

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Half scale
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Double scale
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Similar ratio
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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.