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Finding the Fourth Proportional to 990.16, 1,485.40 and 306

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Solution

The fourth proportional to 990.16, 1,485.40 and 306 is: 459.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.16 : 1,485.40 = 306 : x
  2. Step 2: Convert to fraction form
    990.16/1,485.40 = 306/x
  3. Step 3: Cross multiply
    990.16x = 1,485.40 × 306
  4. Step 4: Simplify right side
    990.16x = 454,532.40
  5. Step 5: Solve for x
    x = 454,532.40/990.16
  6. Step 6: Final answer
    x = 459.05

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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.