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Finding the Fourth Proportional to 990.50, 1,485.02 and 644.18

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Solution

The fourth proportional to 990.50, 1,485.02 and 644.18 is: 965.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.50 : 1,485.02 = 644.18 : x
  2. Step 2: Convert to fraction form
    990.50/1,485.02 = 644.18/x
  3. Step 3: Cross multiply
    990.50x = 1,485.02 × 644.18
  4. Step 4: Simplify right side
    990.50x = 956,614.37
  5. Step 5: Solve for x
    x = 956,614.37/990.50
  6. Step 6: Final answer
    x = 965.79

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Double scale
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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.