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Finding the Fourth Proportional to 856.88, 1,284.80 and 388.16

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Solution

The fourth proportional to 856.88, 1,284.80 and 388.16 is: 582.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.88 : 1,284.80 = 388.16 : x
  2. Step 2: Convert to fraction form
    856.88/1,284.80 = 388.16/x
  3. Step 3: Cross multiply
    856.88x = 1,284.80 × 388.16
  4. Step 4: Simplify right side
    856.88x = 498,707.97
  5. Step 5: Solve for x
    x = 498,707.97/856.88
  6. Step 6: Final answer
    x = 582.00

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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.