Survey

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Transcript

name: Mathematics 146 homework exercises due Tuesday, November 18, 2014 1. Weights in a distant population are normally distributed about a mean of 62 kilograms, with a standard deviation of 4 kilograms. Calculate the weights that correspond to (a) the 10th percentile, (b) the first quartile, and (c) the median. 2. A survey of 900 randomly selected people found that 27% hated eating fish of any kind. Construct a 97% confidence interval for the percent of the population which hates eating fish. 3. During the first week of the quarter, the 21 people in a statistics class had a mean age of 29.63 years, with a (sample) standard deviation of 10.79 years. Assuming that ages across the college are normally distributed, construct a 90% confidence interval for the mean age at the college. (use the t-distribution !) 4. A local pizza shop samples 1000 customers and determines that 70% of the customers found their food to be excellent, with a margin of error of 3%. What is the level of confidence? 5. A sample of heights is drawn from a larger population in which heights are normally distributed. The following heights were observed, along with the number of people with each height: height (cm) frequency 164 2 166 4 168 6 170 4 172 2 (a) calculate the sample’s mean height and the standard deviation of the heights. (b) construct a 95% confidence interval for the entire population’s mean height. (use the t-distribution for part (b) !)