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Finding the Fourth Proportional to 978.28, 1,350.02 and 585.40

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Solution

The fourth proportional to 978.28, 1,350.02 and 585.40 is: 807.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.28 : 1,350.02 = 585.40 : x
  2. Step 2: Convert to fraction form
    978.28/1,350.02 = 585.40/x
  3. Step 3: Cross multiply
    978.28x = 1,350.02 × 585.40
  4. Step 4: Simplify right side
    978.28x = 790,301.71
  5. Step 5: Solve for x
    x = 790,301.71/978.28
  6. Step 6: Final answer
    x = 807.85

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.