Question

Justin did push-ups for the past 555 days.The following data points are the number of push-ups he did each day.

Answer 1

Answer: σ: 2.76

Step-by-step explanation:

Count, N: 5

Sum, Σx: 125

Mean, μ: 25

Variance, σ2:  7.6

Steps

look at attached pic for formula

σ^2 = $\frac{Σ(xi - μ)^{2} }{N}$

$\frac{(21 - 25)2 + ... + (29 - 25)2}{5}$

⇒ $\frac{38}{5}$

⇒ 7.6

σ =  $\sqrt{7.6}$

⇒   2.756809750418

⇒ or 2.76