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Finding the Fourth Proportional to 864.66, 1,297.18 and 287.40

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Solution

The fourth proportional to 864.66, 1,297.18 and 287.40 is: 431.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.66 : 1,297.18 = 287.40 : x
  2. Step 2: Convert to fraction form
    864.66/1,297.18 = 287.40/x
  3. Step 3: Cross multiply
    864.66x = 1,297.18 × 287.40
  4. Step 4: Simplify right side
    864.66x = 372,809.53
  5. Step 5: Solve for x
    x = 372,809.53/864.66
  6. Step 6: Final answer
    x = 431.16

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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.