Home / 1,390.39-2,085.57-1,321.18

Finding the Fourth Proportional to 1,390.39, 2,085.57 and 1,321.18

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Solution

The fourth proportional to 1,390.39, 2,085.57 and 1,321.18 is: 1,981.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,390.39 : 2,085.57 = 1,321.18 : x
  2. Step 2: Convert to fraction form
    1,390.39/2,085.57 = 1,321.18/x
  3. Step 3: Cross multiply
    1,390.39x = 2,085.57 × 1,321.18
  4. Step 4: Simplify right side
    1,390.39x = 2,755,413.37
  5. Step 5: Solve for x
    x = 2,755,413.37/1,390.39
  6. Step 6: Final answer
    x = 1,981.76

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1.5x scale

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.