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Finding the Fourth Proportional to 810.81, 1,117.80 and 611.55

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Solution

The fourth proportional to 810.81, 1,117.80 and 611.55 is: 843.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.81 : 1,117.80 = 611.55 : x
  2. Step 2: Convert to fraction form
    810.81/1,117.80 = 611.55/x
  3. Step 3: Cross multiply
    810.81x = 1,117.80 × 611.55
  4. Step 4: Simplify right side
    810.81x = 683,590.59
  5. Step 5: Solve for x
    x = 683,590.59/810.81
  6. Step 6: Final answer
    x = 843.10

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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.