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Finding the Fourth Proportional to 1,145.50, 1,581.20 and 679.75

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Solution

The fourth proportional to 1,145.50, 1,581.20 and 679.75 is: 938.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,145.50 : 1,581.20 = 679.75 : x
  2. Step 2: Convert to fraction form
    1,145.50/1,581.20 = 679.75/x
  3. Step 3: Cross multiply
    1,145.50x = 1,581.20 × 679.75
  4. Step 4: Simplify right side
    1,145.50x = 1,074,820.70
  5. Step 5: Solve for x
    x = 1,074,820.70/1,145.50
  6. Step 6: Final answer
    x = 938.30

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Double scale
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1.5x scale

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.