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Finding the Fourth Proportional to 1,397.79, 1,929.29 and 808.66

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Solution

The fourth proportional to 1,397.79, 1,929.29 and 808.66 is: 1,116.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,397.79 : 1,929.29 = 808.66 : x
  2. Step 2: Convert to fraction form
    1,397.79/1,929.29 = 808.66/x
  3. Step 3: Cross multiply
    1,397.79x = 1,929.29 × 808.66
  4. Step 4: Simplify right side
    1,397.79x = 1,560,139.65
  5. Step 5: Solve for x
    x = 1,560,139.65/1,397.79
  6. Step 6: Final answer
    x = 1,116.15

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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.