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Finding the Fourth Proportional to 1,315.58, 1,815.30 and 784.30

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Solution

The fourth proportional to 1,315.58, 1,815.30 and 784.30 is: 1,082.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,315.58 : 1,815.30 = 784.30 : x
  2. Step 2: Convert to fraction form
    1,315.58/1,815.30 = 784.30/x
  3. Step 3: Cross multiply
    1,315.58x = 1,815.30 × 784.30
  4. Step 4: Simplify right side
    1,315.58x = 1,423,739.79
  5. Step 5: Solve for x
    x = 1,423,739.79/1,315.58
  6. Step 6: Final answer
    x = 1,082.21

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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.