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Finding the Fourth Proportional to 500.45, 690.65 and 279.43

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Solution

The fourth proportional to 500.45, 690.65 and 279.43 is: 385.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    500.45 : 690.65 = 279.43 : x
  2. Step 2: Convert to fraction form
    500.45/690.65 = 279.43/x
  3. Step 3: Cross multiply
    500.45x = 690.65 × 279.43
  4. Step 4: Simplify right side
    500.45x = 192,986.25
  5. Step 5: Solve for x
    x = 192,986.25/500.45
  6. Step 6: Final answer
    x = 385.63

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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.