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Finding the Fourth Proportional to 1,987.30, 2,981.08 and 947.12

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Solution

The fourth proportional to 1,987.30, 2,981.08 and 947.12 is: 1,420.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,987.30 : 2,981.08 = 947.12 : x
  2. Step 2: Convert to fraction form
    1,987.30/2,981.08 = 947.12/x
  3. Step 3: Cross multiply
    1,987.30x = 2,981.08 × 947.12
  4. Step 4: Simplify right side
    1,987.30x = 2,823,440.49
  5. Step 5: Solve for x
    x = 2,823,440.49/1,987.30
  6. Step 6: Final answer
    x = 1,420.75

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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.