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Finding the Fourth Proportional to 669.40, 923.74 and 389.64

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Solution

The fourth proportional to 669.40, 923.74 and 389.64 is: 537.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.40 : 923.74 = 389.64 : x
  2. Step 2: Convert to fraction form
    669.40/923.74 = 389.64/x
  3. Step 3: Cross multiply
    669.40x = 923.74 × 389.64
  4. Step 4: Simplify right side
    669.40x = 359,926.05
  5. Step 5: Solve for x
    x = 359,926.05/669.40
  6. Step 6: Final answer
    x = 537.68

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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.