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Finding the Fourth Proportional to 878.30, 1,212.18 and 505.28

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Solution

The fourth proportional to 878.30, 1,212.18 and 505.28 is: 697.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.30 : 1,212.18 = 505.28 : x
  2. Step 2: Convert to fraction form
    878.30/1,212.18 = 505.28/x
  3. Step 3: Cross multiply
    878.30x = 1,212.18 × 505.28
  4. Step 4: Simplify right side
    878.30x = 612,490.31
  5. Step 5: Solve for x
    x = 612,490.31/878.30
  6. Step 6: Final answer
    x = 697.36

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.