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Finding the Fourth Proportional to 745.40, 1,120.84 and 380.90

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Solution

The fourth proportional to 745.40, 1,120.84 and 380.90 is: 572.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    745.40 : 1,120.84 = 380.90 : x
  2. Step 2: Convert to fraction form
    745.40/1,120.84 = 380.90/x
  3. Step 3: Cross multiply
    745.40x = 1,120.84 × 380.90
  4. Step 4: Simplify right side
    745.40x = 426,929.81
  5. Step 5: Solve for x
    x = 426,929.81/745.40
  6. Step 6: Final answer
    x = 572.75

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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.