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Finding the Fourth Proportional to 678.51, 1,017.98 and 288.31

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Solution

The fourth proportional to 678.51, 1,017.98 and 288.31 is: 432.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.51 : 1,017.98 = 288.31 : x
  2. Step 2: Convert to fraction form
    678.51/1,017.98 = 288.31/x
  3. Step 3: Cross multiply
    678.51x = 1,017.98 × 288.31
  4. Step 4: Simplify right side
    678.51x = 293,493.81
  5. Step 5: Solve for x
    x = 293,493.81/678.51
  6. Step 6: Final answer
    x = 432.56

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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.