Home / 395.21-545.39-215.76

Finding the Fourth Proportional to 395.21, 545.39 and 215.76

Calculator

Solution

The fourth proportional to 395.21, 545.39 and 215.76 is: 297.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    395.21 : 545.39 = 215.76 : x
  2. Step 2: Convert to fraction form
    395.21/545.39 = 215.76/x
  3. Step 3: Cross multiply
    395.21x = 545.39 × 215.76
  4. Step 4: Simplify right side
    395.21x = 117,673.89
  5. Step 5: Solve for x
    x = 117,673.89/395.21
  6. Step 6: Final answer
    x = 297.75

Related Problems

Find fourth proportional to 197.61, 272.70 and 107.88
Half scale
Find fourth proportional to 790.43, 1,090.79 and 431.52
Double scale
Find fourth proportional to 396.21, 546.77 and 216.76
Similar ratio
Find fourth proportional to 592.82, 818.09 and 323.64
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.