Formula

3. Harmonic mean `= n/( 1/x_1 + 1/x_2 + 1/x_3 + ... + 1/x_n )`

---

Examples
1. Find Harmonic mean for data `20,30`

Solution:
HM `=N/(1/x_1+1/x_2)`

`=2/(1/20+1/30)`

After solving, we get
HM `=24`

---

2. Find Harmonic mean for data `60,40`

Solution:
HM `=N/(1/x_1+1/x_2)`

`=2/(1/60+1/40)`

After solving, we get
HM `=48`

---

3. Find Harmonic mean for data `2,4,8`

Solution:
HM `=N/(1/x_1+1/x_2+1/x_3)`

`=3/(1/2+1/4+1/8)`

After solving, we get
HM `=3.4286`

---

4. Find Harmonic mean for data `2,3,4,5`

Solution:
HM `=N/(1/x_1+1/x_2+1/x_3+1/x_4)`

`=4/(1/2+1/3+1/4+1/5)`

After solving, we get
HM `=3.1169`

---

5. Find Harmonic mean for data `2,3,4,5,6`

Solution:
HM `=N/(1/x_1+1/x_2+1/x_3+1/x_4+1/x_5)`

`=5/(1/2+1/3+1/4+1/5+1/6)`

After solving, we get
HM `=3.4483`

---

---