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Finding the Fourth Proportional to 1,289.95, 1,934.28 and 919.55

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Solution

The fourth proportional to 1,289.95, 1,934.28 and 919.55 is: 1,378.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.95 : 1,934.28 = 919.55 : x
  2. Step 2: Convert to fraction form
    1,289.95/1,934.28 = 919.55/x
  3. Step 3: Cross multiply
    1,289.95x = 1,934.28 × 919.55
  4. Step 4: Simplify right side
    1,289.95x = 1,778,667.17
  5. Step 5: Solve for x
    x = 1,778,667.17/1,289.95
  6. Step 6: Final answer
    x = 1,378.87

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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.