Home / 201.79-278.40-128.14

Finding the Fourth Proportional to 201.79, 278.40 and 128.14

Calculator

Solution

The fourth proportional to 201.79, 278.40 and 128.14 is: 176.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    201.79 : 278.40 = 128.14 : x
  2. Step 2: Convert to fraction form
    201.79/278.40 = 128.14/x
  3. Step 3: Cross multiply
    201.79x = 278.40 × 128.14
  4. Step 4: Simplify right side
    201.79x = 35,673.48
  5. Step 5: Solve for x
    x = 35,673.48/201.79
  6. Step 6: Final answer
    x = 176.79

Related Problems

Find fourth proportional to 100.89, 139.20 and 64.07
Half scale
Find fourth proportional to 403.58, 556.80 and 256.28
Double scale
Find fourth proportional to 202.79, 279.78 and 129.14
Similar ratio
Find fourth proportional to 302.68, 417.60 and 192.21
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.