Home / 202.55-279.42-128.79

Finding the Fourth Proportional to 202.55, 279.42 and 128.79

Calculator

Solution

The fourth proportional to 202.55, 279.42 and 128.79 is: 177.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    202.55 : 279.42 = 128.79 : x
  2. Step 2: Convert to fraction form
    202.55/279.42 = 128.79/x
  3. Step 3: Cross multiply
    202.55x = 279.42 × 128.79
  4. Step 4: Simplify right side
    202.55x = 35,986.50
  5. Step 5: Solve for x
    x = 35,986.50/202.55
  6. Step 6: Final answer
    x = 177.67

Related Problems

Find fourth proportional to 101.27, 139.71 and 64.40
Half scale
Find fourth proportional to 405.09, 558.84 and 257.58
Double scale
Find fourth proportional to 203.55, 280.80 and 129.79
Similar ratio
Find fourth proportional to 303.82, 419.13 and 193.19
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.