Answer: 0.8749
Step-by-step explanation:
Given, The time, X minutes, taken by Tim to install a satellite dish is assumed to be a normal random variable with mean 127 and standard deviation 20.
Let x be the time taken by Tim to install a satellite dish.
Then, the probability that Tim will takes less than 150 minutes to install a satellite dish.
[tex]P(x<150)=P(\dfrac{x-\text{Mean}}{\text{Standard deviation}}<\dfrac{150-127}{20})\\\\=P(z<1.15)\ \ \ [z=\dfrac{x-\text{Mean}}{\text{Standard deviation}}]\\\\=0.8749\ [\text{By z-table}][/tex]
hence, the required probability is 0.8749.
