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Finding the Fourth Proportional to 856.58, 1,283.75 and 387.71

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Solution

The fourth proportional to 856.58, 1,283.75 and 387.71 is: 581.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.58 : 1,283.75 = 387.71 : x
  2. Step 2: Convert to fraction form
    856.58/1,283.75 = 387.71/x
  3. Step 3: Cross multiply
    856.58x = 1,283.75 × 387.71
  4. Step 4: Simplify right side
    856.58x = 497,714.36
  5. Step 5: Solve for x
    x = 497,714.36/856.58
  6. Step 6: Final answer
    x = 581.05

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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.