Home / 826.80-1,238.64-690.72

Finding the Fourth Proportional to 826.80, 1,238.64 and 690.72

Calculator

Solution

The fourth proportional to 826.80, 1,238.64 and 690.72 is: 1,034.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.80 : 1,238.64 = 690.72 : x
  2. Step 2: Convert to fraction form
    826.80/1,238.64 = 690.72/x
  3. Step 3: Cross multiply
    826.80x = 1,238.64 × 690.72
  4. Step 4: Simplify right side
    826.80x = 855,553.42
  5. Step 5: Solve for x
    x = 855,553.42/826.80
  6. Step 6: Final answer
    x = 1,034.78

Related Problems

Find fourth proportional to 413.40, 619.32 and 345.36
Half scale
Find fourth proportional to 1,653.60, 2,477.28 and 1,381.44
Double scale
Find fourth proportional to 827.80, 1,240.14 and 691.72
Similar ratio
Find fourth proportional to 1,240.20, 1,857.96 and 1,036.08
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.