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Finding the Fourth Proportional to 785.40, 1,177.18 and 578.05

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Solution

The fourth proportional to 785.40, 1,177.18 and 578.05 is: 866.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.40 : 1,177.18 = 578.05 : x
  2. Step 2: Convert to fraction form
    785.40/1,177.18 = 578.05/x
  3. Step 3: Cross multiply
    785.40x = 1,177.18 × 578.05
  4. Step 4: Simplify right side
    785.40x = 680,460.12
  5. Step 5: Solve for x
    x = 680,460.12/785.40
  6. Step 6: Final answer
    x = 866.39

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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.