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Finding the Fourth Proportional to 415.79, 570.38 and 390.95

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Solution

The fourth proportional to 415.79, 570.38 and 390.95 is: 536.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.79 : 570.38 = 390.95 : x
  2. Step 2: Convert to fraction form
    415.79/570.38 = 390.95/x
  3. Step 3: Cross multiply
    415.79x = 570.38 × 390.95
  4. Step 4: Simplify right side
    415.79x = 222,988.11
  5. Step 5: Solve for x
    x = 222,988.11/415.79
  6. Step 6: Final answer
    x = 536.30

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.