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Finding the Fourth Proportional to 1,131.40, 1,561.40 and 634.20

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Solution

The fourth proportional to 1,131.40, 1,561.40 and 634.20 is: 875.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,131.40 : 1,561.40 = 634.20 : x
  2. Step 2: Convert to fraction form
    1,131.40/1,561.40 = 634.20/x
  3. Step 3: Cross multiply
    1,131.40x = 1,561.40 × 634.20
  4. Step 4: Simplify right side
    1,131.40x = 990,236.71
  5. Step 5: Solve for x
    x = 990,236.71/1,131.40
  6. Step 6: Final answer
    x = 875.23

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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.