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Finding the Fourth Proportional to 388.75, 534.64 and 309.13

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Solution

The fourth proportional to 388.75, 534.64 and 309.13 is: 425.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.75 : 534.64 = 309.13 : x
  2. Step 2: Convert to fraction form
    388.75/534.64 = 309.13/x
  3. Step 3: Cross multiply
    388.75x = 534.64 × 309.13
  4. Step 4: Simplify right side
    388.75x = 165,275.99
  5. Step 5: Solve for x
    x = 165,275.99/388.75
  6. Step 6: Final answer
    x = 425.14

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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.