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Finding the Fourth Proportional to 860.90, 1,290.88 and 340.38

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Solution

The fourth proportional to 860.90, 1,290.88 and 340.38 is: 510.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.90 : 1,290.88 = 340.38 : x
  2. Step 2: Convert to fraction form
    860.90/1,290.88 = 340.38/x
  3. Step 3: Cross multiply
    860.90x = 1,290.88 × 340.38
  4. Step 4: Simplify right side
    860.90x = 439,381.58
  5. Step 5: Solve for x
    x = 439,381.58/860.90
  6. Step 6: Final answer
    x = 510.37

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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.