Home / 610.40-842.19-389.57

Finding the Fourth Proportional to 610.40, 842.19 and 389.57

Calculator

Solution

The fourth proportional to 610.40, 842.19 and 389.57 is: 537.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    610.40 : 842.19 = 389.57 : x
  2. Step 2: Convert to fraction form
    610.40/842.19 = 389.57/x
  3. Step 3: Cross multiply
    610.40x = 842.19 × 389.57
  4. Step 4: Simplify right side
    610.40x = 328,091.96
  5. Step 5: Solve for x
    x = 328,091.96/610.40
  6. Step 6: Final answer
    x = 537.50

Related Problems

Find fourth proportional to 305.20, 421.10 and 194.79
Half scale
Find fourth proportional to 1,220.80, 1,684.38 and 779.14
Double scale
Find fourth proportional to 611.40, 843.57 and 390.57
Similar ratio
Find fourth proportional to 915.60, 1,263.29 and 584.36
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.