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Finding the Fourth Proportional to 986.80, 1,480.20 and 830.20

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Solution

The fourth proportional to 986.80, 1,480.20 and 830.20 is: 1,245.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    986.80 : 1,480.20 = 830.20 : x
  2. Step 2: Convert to fraction form
    986.80/1,480.20 = 830.20/x
  3. Step 3: Cross multiply
    986.80x = 1,480.20 × 830.20
  4. Step 4: Simplify right side
    986.80x = 1,228,862.04
  5. Step 5: Solve for x
    x = 1,228,862.04/986.80
  6. Step 6: Final answer
    x = 1,245.30

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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.