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Finding the Fourth Proportional to 978.48, 1,460.16 and 869.40

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Solution

The fourth proportional to 978.48, 1,460.16 and 869.40 is: 1,297.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.48 : 1,460.16 = 869.40 : x
  2. Step 2: Convert to fraction form
    978.48/1,460.16 = 869.40/x
  3. Step 3: Cross multiply
    978.48x = 1,460.16 × 869.40
  4. Step 4: Simplify right side
    978.48x = 1,269,463.10
  5. Step 5: Solve for x
    x = 1,269,463.10/978.48
  6. Step 6: Final answer
    x = 1,297.38

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.