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Finding the Fourth Proportional to 642.95, 964.58 and 278.15

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Solution

The fourth proportional to 642.95, 964.58 and 278.15 is: 417.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.95 : 964.58 = 278.15 : x
  2. Step 2: Convert to fraction form
    642.95/964.58 = 278.15/x
  3. Step 3: Cross multiply
    642.95x = 964.58 × 278.15
  4. Step 4: Simplify right side
    642.95x = 268,291.71
  5. Step 5: Solve for x
    x = 268,291.71/642.95
  6. Step 6: Final answer
    x = 417.28

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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.