1. BELL WORK (8 minutes) 1. Use Substitution to solve: y = 19 – x 10x – 7y = 20 1. Your lemonade jar can hold 18 cups total. If the ratio of lemon juice to water is 9 to 4, how many cups of lemon juice do you need if you want to make enough lemonade to fill the jar? Round to nearest tenth and use the Algebraic way Feb 21, 2008

2. BELL WORK Answers 1. 1920 pints per minute 4 gal x 4 qt x 2 pt x 60 sec = 1 sec 1 gal 1 qt 1 min 2. 12.5 cups 9 = J_ 13 18 Lemon juice (PART) Total in jar (WHOLE)

3. 8.11.2 Judge validity of data based on data collection method Judge validity of data based on data collection method

4. Data Collection Method Seeing some fish swimming in the lake, Angel scoops one out with a small net, then throws it back. It's a male. Angel then scoops out and throws back another fish, this time a female. Excitedly, Angel says, “This lake must have an equal amount of male and female fishes! I think the ratio of females to males is 1 to 1." Discuss in your color group if Angel is correct in her reasoning. Why or why not? If she is wrong, what can she do to get a better estimate of females to males?

5. Team Answers She might be right but she needs to catch more fish for more accurate ratio She might be right but she needs to catch more fish for more accurate ratio She is wrong because the survey is not wide enough (sample needs to be larger) She is wrong because the survey is not wide enough (sample needs to be larger) Needs samples from different locations in lake Needs samples from different locations in lake She is wrong because she assumed that the 2 fish represented all the fish in the lake She is wrong because she assumed that the 2 fish represented all the fish in the lake She should either keep the fish to the side OR put a tag/marker on it She should either keep the fish to the side OR put a tag/marker on it

6. Who do I collect data from? Population Population The group that you want to find information about The group that you want to find information about EXAMPLE: fish in the lake EXAMPLE: fish in the lake Sample Sample The group that you are actually going to collect data from needs to be: The group that you are actually going to collect data from needs to be: 1. Similar to the population 2. As big as possible Why? Because sometimes the population is HUGE Why? Because sometimes the population is HUGE EXAMPLE: Angel’s 2 scoops into the lake EXAMPLE: Angel’s 2 scoops into the lake

7. How do I collect the data? Data Collection Method Data Collection Method How you collect the data (information) depends on the situation and population How you collect the data (information) depends on the situation and population EXAMPLES: scooping fish, surveying (asking questions), observing (watching), etc. EXAMPLES: scooping fish, surveying (asking questions), observing (watching), etc. Be Random! Be Random! You have to randomly choose your sample so that your data is not biased (unfair) You have to randomly choose your sample so that your data is not biased (unfair) EXAMPLE: Scooping fish from only one section of the lake (Maybe a lot of females hang out there… so your information would be biased and UNFAIR to the males) EXAMPLE: Scooping fish from only one section of the lake (Maybe a lot of females hang out there… so your information would be biased and UNFAIR to the males)

8. Get the Scoop! Angel decides to test her hypothesis (educated guess) by making more scoops in the lake. Angel decides to test her hypothesis (educated guess) by making more scoops in the lake. http://mathforum.org/escotpow/print_puz zler.ehtml?puzzle=41#Open Java http://mathforum.org/escotpow/print_puz zler.ehtml?puzzle=41#Open Java