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Finding the Fourth Proportional to 1,315.09, 1,971.15 and 621.10

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Solution

The fourth proportional to 1,315.09, 1,971.15 and 621.10 is: 930.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,315.09 : 1,971.15 = 621.10 : x
  2. Step 2: Convert to fraction form
    1,315.09/1,971.15 = 621.10/x
  3. Step 3: Cross multiply
    1,315.09x = 1,971.15 × 621.10
  4. Step 4: Simplify right side
    1,315.09x = 1,224,281.27
  5. Step 5: Solve for x
    x = 1,224,281.27/1,315.09
  6. Step 6: Final answer
    x = 930.95

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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.