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Finding the Fourth Proportional to 1,438, 1,984.26 and 808.40

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Solution

The fourth proportional to 1,438, 1,984.26 and 808.40 is: 1,115.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,438 : 1,984.26 = 808.40 : x
  2. Step 2: Convert to fraction form
    1,438/1,984.26 = 808.40/x
  3. Step 3: Cross multiply
    1,438x = 1,984.26 × 808.40
  4. Step 4: Simplify right side
    1,438x = 1,604,075.78
  5. Step 5: Solve for x
    x = 1,604,075.78/1,438
  6. Step 6: Final answer
    x = 1,115.49

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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.