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Finding the Fourth Proportional to 840.91, 1,260.28 and 678.91

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Solution

The fourth proportional to 840.91, 1,260.28 and 678.91 is: 1,017.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.91 : 1,260.28 = 678.91 : x
  2. Step 2: Convert to fraction form
    840.91/1,260.28 = 678.91/x
  3. Step 3: Cross multiply
    840.91x = 1,260.28 × 678.91
  4. Step 4: Simplify right side
    840.91x = 855,616.69
  5. Step 5: Solve for x
    x = 855,616.69/840.91
  6. Step 6: Final answer
    x = 1,017.49

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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.