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Finding the Fourth Proportional to 856.21, 1,284.17 and 279.08

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Solution

The fourth proportional to 856.21, 1,284.17 and 279.08 is: 418.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.21 : 1,284.17 = 279.08 : x
  2. Step 2: Convert to fraction form
    856.21/1,284.17 = 279.08/x
  3. Step 3: Cross multiply
    856.21x = 1,284.17 × 279.08
  4. Step 4: Simplify right side
    856.21x = 358,386.16
  5. Step 5: Solve for x
    x = 358,386.16/856.21
  6. Step 6: Final answer
    x = 418.57

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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.