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Finding the Fourth Proportional to 830.60, 1,237.29 and 811.40

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Solution

The fourth proportional to 830.60, 1,237.29 and 811.40 is: 1,208.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.60 : 1,237.29 = 811.40 : x
  2. Step 2: Convert to fraction form
    830.60/1,237.29 = 811.40/x
  3. Step 3: Cross multiply
    830.60x = 1,237.29 × 811.40
  4. Step 4: Simplify right side
    830.60x = 1,003,937.11
  5. Step 5: Solve for x
    x = 1,003,937.11/830.60
  6. Step 6: Final answer
    x = 1,208.69

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.