Home / 405-558.91-221

Finding the Fourth Proportional to 405, 558.91 and 221

Calculator

Solution

The fourth proportional to 405, 558.91 and 221 is: 304.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    405 : 558.91 = 221 : x
  2. Step 2: Convert to fraction form
    405/558.91 = 221/x
  3. Step 3: Cross multiply
    405x = 558.91 × 221
  4. Step 4: Simplify right side
    405x = 123,519.11
  5. Step 5: Solve for x
    x = 123,519.11/405
  6. Step 6: Final answer
    x = 304.99

Related Problems

Find fourth proportional to 202.50, 279.46 and 110.50
Half scale
Find fourth proportional to 810, 1,117.82 and 442
Double scale
Find fourth proportional to 406, 560.29 and 222
Similar ratio
Find fourth proportional to 607.50, 838.37 and 331.50
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.