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Finding the Fourth Proportional to 878.42, 1,317.29 and 439.31

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Solution

The fourth proportional to 878.42, 1,317.29 and 439.31 is: 658.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.42 : 1,317.29 = 439.31 : x
  2. Step 2: Convert to fraction form
    878.42/1,317.29 = 439.31/x
  3. Step 3: Cross multiply
    878.42x = 1,317.29 × 439.31
  4. Step 4: Simplify right side
    878.42x = 578,699.77
  5. Step 5: Solve for x
    x = 578,699.77/878.42
  6. Step 6: Final answer
    x = 658.79

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 (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.