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Finding the Fourth Proportional to 780.18, 1,170.22 and 317.40

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Solution

The fourth proportional to 780.18, 1,170.22 and 317.40 is: 476.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.18 : 1,170.22 = 317.40 : x
  2. Step 2: Convert to fraction form
    780.18/1,170.22 = 317.40/x
  3. Step 3: Cross multiply
    780.18x = 1,170.22 × 317.40
  4. Step 4: Simplify right side
    780.18x = 371,427.83
  5. Step 5: Solve for x
    x = 371,427.83/780.18
  6. Step 6: Final answer
    x = 476.08

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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.