Ch. 15 Review #1

Algebra 2H Statistics Review #1 Name: 1. The number of children of each of the first 44 United States presidents Number of Number of is given in the accompanying table. For this population, determine the Children ( x i ) Presidents ( fi ) following values to the nearest tenth. 0 6 1 3 mean st dev variance ____________ 2 10 € 3 € 6 interquartile range ________ 4 7 5 3 How many of these presidents fall within one standard deviation of 6 5 the mean with regard to number of children? 7 1 8 1 10 1 15 1 2. Conant High School has 17 students on its championship bowling team. Each Score ( x i ) Frequency ( fi ) student bowled one game. The scores are listed in the accompanying table. 140 4 145 3 a. Find, to the nearest tenth, the population standard deviation of these scores. 150 2 €
€ 3 160 170 2 180 2 b. Does the distribution of scores appear to be approximately normal? Explain. 194 1 3. Prison overcrowding is an issue in many states. The table below shows US prison population by year. Year 2000 2005 2006 2007 2008 2009 2010 2011 Prison p
opulation (
in m
illions) 1.316 1.448 1.492 1.517 1.522 1.524 1.518 1.504 a) Which regression model (linear, exponential, log, power) best fits the data? _____________________ b) Using your model, predict the prison population for 2008. 4. Two social studies classes took the same current events examination that was scored on the basis of 100 points. Mr. Wong’s class had a median score of 78 points and a range of 4 points, while Ms. Rizzo’s class had a median score of 78 and a range of 22 points. Explain how these classes could have the same median score while having very different ranges. 5. Evaluate: 5
a. ∑
n=1
3
(−2n +100) b. ∑ (3cos kπ +1) k= 0
€
€
6. A town’s January high temperature averages 36°F with a standard deviation of 10°, while in July the mean high temperature is 74° and the standard deviation is 8°. In which month is it more unusual to have a day with a high temperature of 55°? Explain. 7. Which task is not a component of an observational study? 1) The researcher decides who will make up the sample. 2) The researcher analyzes the data received from the sample. 3) The researcher gathers data from the sample, using surveys or taking measurements. 4) The researcher divides the sample into two groups, with one group acting as a control group. 8. A doctor wants to test the effectiveness of a new drug on her patients. She separates her sample of patients into two groups and administers the drug to only one of these groups. She then compares the results. Which type of study best describes this situation? 1) census 2) survey 3) observation 4) controlled experiment 9. The yearbook staff has designed a survey to learn student opinions on how the yearbook could be improved for this year. If they want to distribute this survey to 100 students and obtain the most reliable data, they should survey 1) every third student sent to the office 2) every third student to enter the library 3) every third student to enter the gym for the basketball game 4) every third student arriving at school in the morning