8) Bottles of a popular cola are supposed to contain 300 milliliters of cola. There is some variation from bottle to bottle because the filling machinery is not perfectly precise. The distribution of the contents is Normal with a standard deviation of = 3ml. An inspector who suspects that the bottler is underfilling measures the contents of six randomly selected bottles from a single day's production. The results are: 299.4 297.7 301.0 298.9 300.2 297.0 Do the data provide convincing evidence that the mean amount of cola in all bottles filled that day is less than the advertised 300ml? 10) An environmentalist group collects a liter of water from each of 45 randomly chosen locations along a stream and measures the amount of dissolved oxygen in each specimen. The mean is 4.62 mg/L. Do the data provide convincing evidence that the stream has a mean dissolved oxygen content of less than 5 mg/L? (Suppose we know that dissolved oxygen varies among locations with = 0.92 mg/L)