Home / 1,289.16-1,778.10-817.20

Finding the Fourth Proportional to 1,289.16, 1,778.10 and 817.20

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Solution

The fourth proportional to 1,289.16, 1,778.10 and 817.20 is: 1,127.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.16 : 1,778.10 = 817.20 : x
  2. Step 2: Convert to fraction form
    1,289.16/1,778.10 = 817.20/x
  3. Step 3: Cross multiply
    1,289.16x = 1,778.10 × 817.20
  4. Step 4: Simplify right side
    1,289.16x = 1,453,063.32
  5. Step 5: Solve for x
    x = 1,453,063.32/1,289.16
  6. Step 6: Final answer
    x = 1,127.14

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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.