Respuesta :
we are asked to determine the probability that a variable x is greater than 119.8. To do that we will assume a normal distribution of probability and use the following relationship:
[tex]P(x>119.8)=1-P(x\le119.8)[/tex]To determine the probability that x is smaller than 119.8 we need first to find the z-score of the data set using the following formula:
[tex]z=\frac{x-\bar{x}}{\sigma}[/tex]Where
[tex]\begin{gathered} \bar{x}\colon\operatorname{mean} \\ \sigma\colon\text{ standard deviation} \end{gathered}[/tex]replacing we get:
[tex]z=\frac{119.8-95.3}{15.4}=1.59[/tex]Now we use this value to look into the chart for probabilities, we get 0.94408. This is the probability that x is smaller than 119.8. Replacing in the initial relationship we get:
[tex]P(x>119.8)=1-0.94408=0.056[/tex]Therefore, the probability is 5.6%.
