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Finding the Fourth Proportional to 830.76, 1,245.38 and 310.40

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Solution

The fourth proportional to 830.76, 1,245.38 and 310.40 is: 465.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.76 : 1,245.38 = 310.40 : x
  2. Step 2: Convert to fraction form
    830.76/1,245.38 = 310.40/x
  3. Step 3: Cross multiply
    830.76x = 1,245.38 × 310.40
  4. Step 4: Simplify right side
    830.76x = 386,565.95
  5. Step 5: Solve for x
    x = 386,565.95/830.76
  6. Step 6: Final answer
    x = 465.32

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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.