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Finding the Fourth Proportional to 1,131.40, 1,561.26 and 665.56

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Solution

The fourth proportional to 1,131.40, 1,561.26 and 665.56 is: 918.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,131.40 : 1,561.26 = 665.56 : x
  2. Step 2: Convert to fraction form
    1,131.40/1,561.26 = 665.56/x
  3. Step 3: Cross multiply
    1,131.40x = 1,561.26 × 665.56
  4. Step 4: Simplify right side
    1,131.40x = 1,039,112.21
  5. Step 5: Solve for x
    x = 1,039,112.21/1,131.40
  6. Step 6: Final answer
    x = 918.43

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Double scale
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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.