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Finding the Fourth Proportional to 856.76, 1,284.86 and 279.50

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Solution

The fourth proportional to 856.76, 1,284.86 and 279.50 is: 419.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.76 : 1,284.86 = 279.50 : x
  2. Step 2: Convert to fraction form
    856.76/1,284.86 = 279.50/x
  3. Step 3: Cross multiply
    856.76x = 1,284.86 × 279.50
  4. Step 4: Simplify right side
    856.76x = 359,118.37
  5. Step 5: Solve for x
    x = 359,118.37/856.76
  6. Step 6: Final answer
    x = 419.16

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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.