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Finding the Fourth Proportional to 1,277.80, 1,917.02 and 412.20

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Solution

The fourth proportional to 1,277.80, 1,917.02 and 412.20 is: 618.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,277.80 : 1,917.02 = 412.20 : x
  2. Step 2: Convert to fraction form
    1,277.80/1,917.02 = 412.20/x
  3. Step 3: Cross multiply
    1,277.80x = 1,917.02 × 412.20
  4. Step 4: Simplify right side
    1,277.80x = 790,195.64
  5. Step 5: Solve for x
    x = 790,195.64/1,277.80
  6. Step 6: Final answer
    x = 618.40

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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.