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Finding the Fourth Proportional to 1,860, 2,790.48 and 690

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Solution

The fourth proportional to 1,860, 2,790.48 and 690 is: 1,035.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,860 : 2,790.48 = 690 : x
  2. Step 2: Convert to fraction form
    1,860/2,790.48 = 690/x
  3. Step 3: Cross multiply
    1,860x = 2,790.48 × 690
  4. Step 4: Simplify right side
    1,860x = 1,925,431.20
  5. Step 5: Solve for x
    x = 1,925,431.20/1,860
  6. Step 6: Final answer
    x = 1,035.18

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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.