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Finding the Fourth Proportional to 830.39, 1,153.98 and 820.13

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Solution

The fourth proportional to 830.39, 1,153.98 and 820.13 is: 1,139.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    830.39 : 1,153.98 = 820.13 : x
  2. Step 2: Convert to fraction form
    830.39/1,153.98 = 820.13/x
  3. Step 3: Cross multiply
    830.39x = 1,153.98 × 820.13
  4. Step 4: Simplify right side
    830.39x = 946,407.85
  5. Step 5: Solve for x
    x = 946,407.85/830.39
  6. Step 6: Final answer
    x = 1,139.72

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.