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Finding the Fourth Proportional to 653.79, 980.78 and 221.07

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Solution

The fourth proportional to 653.79, 980.78 and 221.07 is: 331.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.79 : 980.78 = 221.07 : x
  2. Step 2: Convert to fraction form
    653.79/980.78 = 221.07/x
  3. Step 3: Cross multiply
    653.79x = 980.78 × 221.07
  4. Step 4: Simplify right side
    653.79x = 216,821.03
  5. Step 5: Solve for x
    x = 216,821.03/653.79
  6. Step 6: Final answer
    x = 331.64

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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.