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Finding the Fourth Proportional to 690.89, 1,036.43 and 258

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Solution

The fourth proportional to 690.89, 1,036.43 and 258 is: 387.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.89 : 1,036.43 = 258 : x
  2. Step 2: Convert to fraction form
    690.89/1,036.43 = 258/x
  3. Step 3: Cross multiply
    690.89x = 1,036.43 × 258
  4. Step 4: Simplify right side
    690.89x = 267,397.65
  5. Step 5: Solve for x
    x = 267,397.65/690.89
  6. Step 6: Final answer
    x = 387.04

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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.