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Finding the Fourth Proportional to 1,643, 2,266.80 and 980

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Solution

The fourth proportional to 1,643, 2,266.80 and 980 is: 1,352.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,643 : 2,266.80 = 980 : x
  2. Step 2: Convert to fraction form
    1,643/2,266.80 = 980/x
  3. Step 3: Cross multiply
    1,643x = 2,266.80 × 980
  4. Step 4: Simplify right side
    1,643x = 2,221,464
  5. Step 5: Solve for x
    x = 2,221,464/1,643
  6. Step 6: Final answer
    x = 1,352.08

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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.