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Finding the Fourth Proportional to 780.18, 1,170.54 and 561.39

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Solution

The fourth proportional to 780.18, 1,170.54 and 561.39 is: 842.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.18 : 1,170.54 = 561.39 : x
  2. Step 2: Convert to fraction form
    780.18/1,170.54 = 561.39/x
  3. Step 3: Cross multiply
    780.18x = 1,170.54 × 561.39
  4. Step 4: Simplify right side
    780.18x = 657,129.45
  5. Step 5: Solve for x
    x = 657,129.45/780.18
  6. Step 6: Final answer
    x = 842.28

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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.