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Finding the Fourth Proportional to 840.18, 1,158.80 and 784.30

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Solution

The fourth proportional to 840.18, 1,158.80 and 784.30 is: 1,081.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.18 : 1,158.80 = 784.30 : x
  2. Step 2: Convert to fraction form
    840.18/1,158.80 = 784.30/x
  3. Step 3: Cross multiply
    840.18x = 1,158.80 × 784.30
  4. Step 4: Simplify right side
    840.18x = 908,846.84
  5. Step 5: Solve for x
    x = 908,846.84/840.18
  6. Step 6: Final answer
    x = 1,081.73

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.