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Finding the Fourth Proportional to 653.05, 900.70 and 390.79

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Solution

The fourth proportional to 653.05, 900.70 and 390.79 is: 538.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.05 : 900.70 = 390.79 : x
  2. Step 2: Convert to fraction form
    653.05/900.70 = 390.79/x
  3. Step 3: Cross multiply
    653.05x = 900.70 × 390.79
  4. Step 4: Simplify right side
    653.05x = 351,984.55
  5. Step 5: Solve for x
    x = 351,984.55/653.05
  6. Step 6: Final answer
    x = 538.99

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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.