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Finding the Fourth Proportional to 388.80, 583.40 and 145.40

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Solution

The fourth proportional to 388.80, 583.40 and 145.40 is: 218.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.80 : 583.40 = 145.40 : x
  2. Step 2: Convert to fraction form
    388.80/583.40 = 145.40/x
  3. Step 3: Cross multiply
    388.80x = 583.40 × 145.40
  4. Step 4: Simplify right side
    388.80x = 84,823.81
  5. Step 5: Solve for x
    x = 84,823.81/388.80
  6. Step 6: Final answer
    x = 218.17

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.