Question

commercials is a average of 16 minutes and a standard deviation equals 2.1 minutes. After watching the chanel for a hour randomly you observe the amount of commercials equals to 19 minutes Find the z score for the amount of commercials, round 2 decimals

Answer 1

To answer this question we will use the following formula to compute the z-score:

`\begin{gathered} z=(x-\mu)/(\sigma), \\ \text{where x is the observed value, }\mu\text{ is the mean, and }\sigma\text{ is the standard deviation.} \end{gathered}`

Substituting x=19min, μ=16min, and σ=2.1min we get:

`z=(19\min -16\min )/(2.1\min )\text{.}`

Simplifying the above result we get:

`z=(3)/(2.1)=(10)/(7)\approx1.43.`

Answer: 1.43.