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Finding the Fourth Proportional to 1,370.25, 1,891.28 and 781.13

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Solution

The fourth proportional to 1,370.25, 1,891.28 and 781.13 is: 1,078.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,370.25 : 1,891.28 = 781.13 : x
  2. Step 2: Convert to fraction form
    1,370.25/1,891.28 = 781.13/x
  3. Step 3: Cross multiply
    1,370.25x = 1,891.28 × 781.13
  4. Step 4: Simplify right side
    1,370.25x = 1,477,342.23
  5. Step 5: Solve for x
    x = 1,477,342.23/1,370.25
  6. Step 6: Final answer
    x = 1,078.16

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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.