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Finding the Fourth Proportional to 1,941.72, 2,912.80 and 642.90

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Solution

The fourth proportional to 1,941.72, 2,912.80 and 642.90 is: 964.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,941.72 : 2,912.80 = 642.90 : x
  2. Step 2: Convert to fraction form
    1,941.72/2,912.80 = 642.90/x
  3. Step 3: Cross multiply
    1,941.72x = 2,912.80 × 642.90
  4. Step 4: Simplify right side
    1,941.72x = 1,872,639.12
  5. Step 5: Solve for x
    x = 1,872,639.12/1,941.72
  6. Step 6: Final answer
    x = 964.42

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.