Home / 1,021.20-1,521.63-912.15

Finding the Fourth Proportional to 1,021.20, 1,521.63 and 912.15

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Solution

The fourth proportional to 1,021.20, 1,521.63 and 912.15 is: 1,359.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,021.20 : 1,521.63 = 912.15 : x
  2. Step 2: Convert to fraction form
    1,021.20/1,521.63 = 912.15/x
  3. Step 3: Cross multiply
    1,021.20x = 1,521.63 × 912.15
  4. Step 4: Simplify right side
    1,021.20x = 1,387,954.80
  5. Step 5: Solve for x
    x = 1,387,954.80/1,021.20
  6. Step 6: Final answer
    x = 1,359.14

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.