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Finding the Fourth Proportional to 988.40, 1,363.80 and 693.20

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Solution

The fourth proportional to 988.40, 1,363.80 and 693.20 is: 956.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    988.40 : 1,363.80 = 693.20 : x
  2. Step 2: Convert to fraction form
    988.40/1,363.80 = 693.20/x
  3. Step 3: Cross multiply
    988.40x = 1,363.80 × 693.20
  4. Step 4: Simplify right side
    988.40x = 945,386.16
  5. Step 5: Solve for x
    x = 945,386.16/988.40
  6. Step 6: Final answer
    x = 956.48

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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.