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Finding the Fourth Proportional to 978.23, 1,350.99 and 664.89

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Solution

The fourth proportional to 978.23, 1,350.99 and 664.89 is: 918.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.23 : 1,350.99 = 664.89 : x
  2. Step 2: Convert to fraction form
    978.23/1,350.99 = 664.89/x
  3. Step 3: Cross multiply
    978.23x = 1,350.99 × 664.89
  4. Step 4: Simplify right side
    978.23x = 898,259.74
  5. Step 5: Solve for x
    x = 898,259.74/978.23
  6. Step 6: Final answer
    x = 918.25

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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.