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Finding the Fourth Proportional to 1,988.43, 2,980.82 and 947.78

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Solution

The fourth proportional to 1,988.43, 2,980.82 and 947.78 is: 1,420.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,988.43 : 2,980.82 = 947.78 : x
  2. Step 2: Convert to fraction form
    1,988.43/2,980.82 = 947.78/x
  3. Step 3: Cross multiply
    1,988.43x = 2,980.82 × 947.78
  4. Step 4: Simplify right side
    1,988.43x = 2,825,161.58
  5. Step 5: Solve for x
    x = 2,825,161.58/1,988.43
  6. Step 6: Final answer
    x = 1,420.80

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.