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Finding the Fourth Proportional to 690.80, 953.25 and 428.77

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Solution

The fourth proportional to 690.80, 953.25 and 428.77 is: 591.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.80 : 953.25 = 428.77 : x
  2. Step 2: Convert to fraction form
    690.80/953.25 = 428.77/x
  3. Step 3: Cross multiply
    690.80x = 953.25 × 428.77
  4. Step 4: Simplify right side
    690.80x = 408,720.24
  5. Step 5: Solve for x
    x = 408,720.24/690.80
  6. Step 6: Final answer
    x = 591.66

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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.