the graph shows the distribution of the amount of time (in minutes) people spend watching tv shows on a…

the graph shows the distribution of the amount of time (in minutes) people spend watching tv shows on a popular streaming service. the distribution is approximately normal, with a mean of 71 minutes and a standard deviation of 15 minutes. sixteen percent of people spend more than what amount of time watching tv shows on this streaming service? 41 minutes 56 minutes 86 minutes 101 minutes
Answer
Explanation:
Step1: Recall the empirical rule for normal distribution
The empirical rule states that for a normal distribution:
- Approximately (68%) of the data lies within (1) standard deviation ((\mu\pm\sigma)) of the mean.
- Approximately (95%) of the data lies within (2) standard deviations ((\mu\pm2\sigma)) of the mean.
- Approximately (99.7%) of the data lies within (3) standard deviations ((\mu\pm3\sigma)) of the mean.
The area to the right of (x) is (0.16). Since the total area under the normal curve is (1), and the normal distribution is symmetric about the mean (\mu), we know that (P(X > x)=0.16) is equivalent to (P(X<\mu + z\sigma)=0.84) (because (1 - 0.16=0.84)). From the empirical rule, when (z = 1), (P(\mu-\sigma<X<\mu+\sigma)=0.68) and (P(X<\mu+\sigma)=0.5+\frac{0.68}{2}=0.84)
Step2: Calculate the value of (x)
We are given that (\mu = 71) (mean) and (\sigma=15) (standard deviation). Using the formula (x=\mu + z\sigma), with (z = 1) (from the empirical rule for the (84^{th}) percentile) (x=71+1\times15) (x = 86)
Answer:
86 minutes