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Finding the Fourth Proportional to 853.19, 1,279.40 and 391.12

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Solution

The fourth proportional to 853.19, 1,279.40 and 391.12 is: 586.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    853.19 : 1,279.40 = 391.12 : x
  2. Step 2: Convert to fraction form
    853.19/1,279.40 = 391.12/x
  3. Step 3: Cross multiply
    853.19x = 1,279.40 × 391.12
  4. Step 4: Simplify right side
    853.19x = 500,390.58
  5. Step 5: Solve for x
    x = 500,390.58/853.19
  6. Step 6: Final answer
    x = 586.50

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1.5x scale

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.