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Finding the Fourth Proportional to 678.39, 1,017.59 and 313.08

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Solution

The fourth proportional to 678.39, 1,017.59 and 313.08 is: 469.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.39 : 1,017.59 = 313.08 : x
  2. Step 2: Convert to fraction form
    678.39/1,017.59 = 313.08/x
  3. Step 3: Cross multiply
    678.39x = 1,017.59 × 313.08
  4. Step 4: Simplify right side
    678.39x = 318,587.08
  5. Step 5: Solve for x
    x = 318,587.08/678.39
  6. Step 6: Final answer
    x = 469.62

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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.