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Finding the Fourth Proportional to 1,430.79, 1,974.21 and 870.89

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Solution

The fourth proportional to 1,430.79, 1,974.21 and 870.89 is: 1,201.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,430.79 : 1,974.21 = 870.89 : x
  2. Step 2: Convert to fraction form
    1,430.79/1,974.21 = 870.89/x
  3. Step 3: Cross multiply
    1,430.79x = 1,974.21 × 870.89
  4. Step 4: Simplify right side
    1,430.79x = 1,719,306.61
  5. Step 5: Solve for x
    x = 1,719,306.61/1,430.79
  6. Step 6: Final answer
    x = 1,201.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.