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Finding the Fourth Proportional to 642.65, 964.09 and 257.93

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Solution

The fourth proportional to 642.65, 964.09 and 257.93 is: 386.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.65 : 964.09 = 257.93 : x
  2. Step 2: Convert to fraction form
    642.65/964.09 = 257.93/x
  3. Step 3: Cross multiply
    642.65x = 964.09 × 257.93
  4. Step 4: Simplify right side
    642.65x = 248,662.27
  5. Step 5: Solve for x
    x = 248,662.27/642.65
  6. Step 6: Final answer
    x = 386.94

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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.