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Finding the Fourth Proportional to 1,415.65, 2,122.65 and 428.17

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Solution

The fourth proportional to 1,415.65, 2,122.65 and 428.17 is: 642.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,415.65 : 2,122.65 = 428.17 : x
  2. Step 2: Convert to fraction form
    1,415.65/2,122.65 = 428.17/x
  3. Step 3: Cross multiply
    1,415.65x = 2,122.65 × 428.17
  4. Step 4: Simplify right side
    1,415.65x = 908,855.05
  5. Step 5: Solve for x
    x = 908,855.05/1,415.65
  6. Step 6: Final answer
    x = 642.01

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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.