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Finding the Fourth Proportional to 856.50, 1,284.76 and 279.40

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Solution

The fourth proportional to 856.50, 1,284.76 and 279.40 is: 419.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.50 : 1,284.76 = 279.40 : x
  2. Step 2: Convert to fraction form
    856.50/1,284.76 = 279.40/x
  3. Step 3: Cross multiply
    856.50x = 1,284.76 × 279.40
  4. Step 4: Simplify right side
    856.50x = 358,961.94
  5. Step 5: Solve for x
    x = 358,961.94/856.50
  6. Step 6: Final answer
    x = 419.10

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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.