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Finding the Fourth Proportional to 860.18, 1,187.15 and 720.05

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Solution

The fourth proportional to 860.18, 1,187.15 and 720.05 is: 993.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.18 : 1,187.15 = 720.05 : x
  2. Step 2: Convert to fraction form
    860.18/1,187.15 = 720.05/x
  3. Step 3: Cross multiply
    860.18x = 1,187.15 × 720.05
  4. Step 4: Simplify right side
    860.18x = 854,812.13
  5. Step 5: Solve for x
    x = 854,812.13/860.18
  6. Step 6: Final answer
    x = 993.76

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.