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Finding the Fourth Proportional to 978.90, 1,350.88 and 536.80

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Solution

The fourth proportional to 978.90, 1,350.88 and 536.80 is: 740.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.90 : 1,350.88 = 536.80 : x
  2. Step 2: Convert to fraction form
    978.90/1,350.88 = 536.80/x
  3. Step 3: Cross multiply
    978.90x = 1,350.88 × 536.80
  4. Step 4: Simplify right side
    978.90x = 725,152.38
  5. Step 5: Solve for x
    x = 725,152.38/978.90
  6. Step 6: Final answer
    x = 740.78

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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.