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Finding the Fourth Proportional to 808.95, 1,116.92 and 643.56

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Solution

The fourth proportional to 808.95, 1,116.92 and 643.56 is: 888.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.95 : 1,116.92 = 643.56 : x
  2. Step 2: Convert to fraction form
    808.95/1,116.92 = 643.56/x
  3. Step 3: Cross multiply
    808.95x = 1,116.92 × 643.56
  4. Step 4: Simplify right side
    808.95x = 718,802.46
  5. Step 5: Solve for x
    x = 718,802.46/808.95
  6. Step 6: Final answer
    x = 888.56

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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.