Home / 158.90-218.75-138.09

Finding the Fourth Proportional to 158.90, 218.75 and 138.09

Calculator

Solution

The fourth proportional to 158.90, 218.75 and 138.09 is: 190.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    158.90 : 218.75 = 138.09 : x
  2. Step 2: Convert to fraction form
    158.90/218.75 = 138.09/x
  3. Step 3: Cross multiply
    158.90x = 218.75 × 138.09
  4. Step 4: Simplify right side
    158.90x = 30,206.50
  5. Step 5: Solve for x
    x = 30,206.50/158.90
  6. Step 6: Final answer
    x = 190.10

Related Problems

Find fourth proportional to 79.45, 109.37 and 69.05
Half scale
Find fourth proportional to 317.79, 437.49 and 276.18
Double scale
Find fourth proportional to 159.90, 220.12 and 139.09
Similar ratio
Find fourth proportional to 238.34, 328.12 and 207.14
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.