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Finding the Fourth Proportional to 690.42, 947.49 and 685.56

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Solution

The fourth proportional to 690.42, 947.49 and 685.56 is: 940.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.42 : 947.49 = 685.56 : x
  2. Step 2: Convert to fraction form
    690.42/947.49 = 685.56/x
  3. Step 3: Cross multiply
    690.42x = 947.49 × 685.56
  4. Step 4: Simplify right side
    690.42x = 649,561.24
  5. Step 5: Solve for x
    x = 649,561.24/690.42
  6. Step 6: Final answer
    x = 940.82

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.