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Finding the Fourth Proportional to 810.65, 1,119.23 and 623.80

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Solution

The fourth proportional to 810.65, 1,119.23 and 623.80 is: 861.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.65 : 1,119.23 = 623.80 : x
  2. Step 2: Convert to fraction form
    810.65/1,119.23 = 623.80/x
  3. Step 3: Cross multiply
    810.65x = 1,119.23 × 623.80
  4. Step 4: Simplify right side
    810.65x = 698,175.67
  5. Step 5: Solve for x
    x = 698,175.67/810.65
  6. Step 6: Final answer
    x = 861.25

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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.