To solve this problem, we will use the properties of the normal distribution.
a) To find the probability that a randomly selected container exceeds 765 mL of beer, we need to calculate the z-score corresponding to 765 mL using the formula:
z = \frac{{X - \mu}}{{\sigma}}
where X is the value we are interested in (765 mL), μ is the mean (745 mL), and σ is the standard deviation (8 mL). Substituting these values, we get:
z = \frac{{765 - 745}}{{8}} = \frac{{20}}{{8}} = 2.5
Next, we need to find the area under the normal curve to the right of the z-score of 2.5. We can use a standard normal distribution table or a calculator to find this area.
Using a standard normal distribution table, we find that the area to the right of 2.5 is approximately 0.0062.
Therefore, the probability that a randomly selected container exceeds 765 mL of beer is approximately 0.0062.
b) To find the probability that the beer content of a randomly selected container is between 735 and 755 mL, we need to calculate the z-scores corresponding to 735 mL and 755 mL.
For 735 mL:
z_1 = \frac{{735 - 745}}{{8}} = \frac{{-10}}{{8}} = -1.25
For 755 mL:
z_2 = \frac{{755 - 745}}{{8}} = \frac{{10}}{{8}} = 1.25
Next, we need to find the area under the normal curve between these two z-scores. We can subtract the area to the left of -1.25 from the area to the left of 1.25. Again, we can use a standard normal distribution table or a calculator to find these areas.
Using a standard normal distribution table, we find that the area to the left of -1.25 is approximately 0.1056, and the area to the left of 1.25 is approximately 0.8944.
Therefore, the probability that the beer content of a randomly selected container is between 735 and 755 mL is approximately 0.8944 - 0.1056 = 0.7888.
Answer:
a) The probability that a randomly selected container exceeds 765 mL of beer is approximately 0.0062.
b) The probability that the beer content of a randomly selected container is between 735 and 755 mL is approximately 0.7888.