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Finding the Fourth Proportional to 645.77, 890.71 and 396.77

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Solution

The fourth proportional to 645.77, 890.71 and 396.77 is: 547.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.77 : 890.71 = 396.77 : x
  2. Step 2: Convert to fraction form
    645.77/890.71 = 396.77/x
  3. Step 3: Cross multiply
    645.77x = 890.71 × 396.77
  4. Step 4: Simplify right side
    645.77x = 353,401.56
  5. Step 5: Solve for x
    x = 353,401.56/645.77
  6. Step 6: Final answer
    x = 547.25

Related Problems

Find fourth proportional to 322.89, 445.35 and 198.38
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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.