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Finding the Fourth Proportional to 780.38, 1,170.26 and 318.00

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Solution

The fourth proportional to 780.38, 1,170.26 and 318.00 is: 476.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.38 : 1,170.26 = 318.00 : x
  2. Step 2: Convert to fraction form
    780.38/1,170.26 = 318.00/x
  3. Step 3: Cross multiply
    780.38x = 1,170.26 × 318.00
  4. Step 4: Simplify right side
    780.38x = 372,145.17
  5. Step 5: Solve for x
    x = 372,145.17/780.38
  6. Step 6: Final answer
    x = 476.88

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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.