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Finding the Fourth Proportional to 780.13, 1,170.05 and 318.23

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Solution

The fourth proportional to 780.13, 1,170.05 and 318.23 is: 477.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.13 : 1,170.05 = 318.23 : x
  2. Step 2: Convert to fraction form
    780.13/1,170.05 = 318.23/x
  3. Step 3: Cross multiply
    780.13x = 1,170.05 × 318.23
  4. Step 4: Simplify right side
    780.13x = 372,341.96
  5. Step 5: Solve for x
    x = 372,341.96/780.13
  6. Step 6: Final answer
    x = 477.28

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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.