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Finding the Fourth Proportional to 790.21, 1,090.99 and 643.19

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Solution

The fourth proportional to 790.21, 1,090.99 and 643.19 is: 888.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    790.21 : 1,090.99 = 643.19 : x
  2. Step 2: Convert to fraction form
    790.21/1,090.99 = 643.19/x
  3. Step 3: Cross multiply
    790.21x = 1,090.99 × 643.19
  4. Step 4: Simplify right side
    790.21x = 701,717.15
  5. Step 5: Solve for x
    x = 701,717.15/790.21
  6. Step 6: Final answer
    x = 888.02

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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.