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Finding the Fourth Proportional to 1,620.78, 2,431.48 and 646.89

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Solution

The fourth proportional to 1,620.78, 2,431.48 and 646.89 is: 970.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,620.78 : 2,431.48 = 646.89 : x
  2. Step 2: Convert to fraction form
    1,620.78/2,431.48 = 646.89/x
  3. Step 3: Cross multiply
    1,620.78x = 2,431.48 × 646.89
  4. Step 4: Simplify right side
    1,620.78x = 1,572,908.41
  5. Step 5: Solve for x
    x = 1,572,908.41/1,620.78
  6. Step 6: Final answer
    x = 970.46

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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.