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Finding the Fourth Proportional to 720.08, 1,074.51 and 642.51

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Solution

The fourth proportional to 720.08, 1,074.51 and 642.51 is: 958.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.08 : 1,074.51 = 642.51 : x
  2. Step 2: Convert to fraction form
    720.08/1,074.51 = 642.51/x
  3. Step 3: Cross multiply
    720.08x = 1,074.51 × 642.51
  4. Step 4: Simplify right side
    720.08x = 690,382.89
  5. Step 5: Solve for x
    x = 690,382.89/720.08
  6. Step 6: Final answer
    x = 958.76

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.