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Finding the Fourth Proportional to 690.72, 945.57 and 688.44

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Solution

The fourth proportional to 690.72, 945.57 and 688.44 is: 942.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.72 : 945.57 = 688.44 : x
  2. Step 2: Convert to fraction form
    690.72/945.57 = 688.44/x
  3. Step 3: Cross multiply
    690.72x = 945.57 × 688.44
  4. Step 4: Simplify right side
    690.72x = 650,968.21
  5. Step 5: Solve for x
    x = 650,968.21/690.72
  6. Step 6: Final answer
    x = 942.45

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Double scale
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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.