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Finding the Fourth Proportional to 1,315.80, 1,815.77 and 818.25

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Solution

The fourth proportional to 1,315.80, 1,815.77 and 818.25 is: 1,129.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,315.80 : 1,815.77 = 818.25 : x
  2. Step 2: Convert to fraction form
    1,315.80/1,815.77 = 818.25/x
  3. Step 3: Cross multiply
    1,315.80x = 1,815.77 × 818.25
  4. Step 4: Simplify right side
    1,315.80x = 1,485,755.85
  5. Step 5: Solve for x
    x = 1,485,755.85/1,315.80
  6. Step 6: Final answer
    x = 1,129.17

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.