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Finding the Fourth Proportional to 810.80, 1,118.40 and 636.56

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Solution

The fourth proportional to 810.80, 1,118.40 and 636.56 is: 878.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.80 : 1,118.40 = 636.56 : x
  2. Step 2: Convert to fraction form
    810.80/1,118.40 = 636.56/x
  3. Step 3: Cross multiply
    810.80x = 1,118.40 × 636.56
  4. Step 4: Simplify right side
    810.80x = 711,928.70
  5. Step 5: Solve for x
    x = 711,928.70/810.80
  6. Step 6: Final answer
    x = 878.06

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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.