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Finding the Fourth Proportional to 919.10, 1,379.55 and 457.40

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Solution

The fourth proportional to 919.10, 1,379.55 and 457.40 is: 686.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.10 : 1,379.55 = 457.40 : x
  2. Step 2: Convert to fraction form
    919.10/1,379.55 = 457.40/x
  3. Step 3: Cross multiply
    919.10x = 1,379.55 × 457.40
  4. Step 4: Simplify right side
    919.10x = 631,006.17
  5. Step 5: Solve for x
    x = 631,006.17/919.10
  6. Step 6: Final answer
    x = 686.55

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Double scale
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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.