lab

Exercise 1: Data Interpretation Dissolved oxygen is oxygen that is trapped in a fluid. Since many living organisms require oxygen to survive, it is a necessary component of water systems (streams, lakes, rivers, etc.). Dissolved oxygen is measured in units of parts per million (ppm). Examine the data in Table 4, which shows the amount of dissolved oxygen present in a body of water and the number of fish observed in the sample. Then, answer the questions below. Table 4: Water Quality vs. Fish Population Dissolved Oxygen (ppm) 0 2 4 6 8 10 12 14 16 18 Number of Fish Observed 0 1 3 10 12 13 15 10 12 13 What patterns do you observe based on the information in Table 4? Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water. What would your experimental approach be to test this hypothesis? What would be the independent and dependent variables? What would be your control? Exercise 2: Testable Observations Determine which of the observations below are testable. For those that are testable: Determine if the observation is qualitative or quantitative. Write a hypothesis and a null hypothesis. What would be your experimental approach? What are the dependent and independent variables? What are your controls - both positive and negative? How will you collect your data? How will you present your data (e.g., charts, graphs, types)? How will you analyze your data? Observations A plant grows 3 cm faster per day when placed on a window sill than it does when placed on a coffee table in the middle of the living room. The bank teller with brown hair and brown eyes is taller than the other tellers. When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she eats fatty foods and does not exercise. The Italian restaurant across the street closes at 9 pm, but the restaurant two blocks away closes at 10 pm. For the past two days, the clouds have come out at 3 pm, and it has started raining at 3:15 pm. George did not sleep at all the night following the start of Daylight Savings Time. Exercise 3: Conversion Use Figure 9 to convert each value into the designated units. Figure 9: Conversions for temperature, time, mass, and length. 46,756,790 mg = _______ kg 5.6 hours = ________ seconds 13.5 cm = ________ inches 47 °F = _______ °C Exercise 4: Accuracy and Precision Determine whether the following statements are accurate, precise, both, or neither. Circle your answer. During gym class, four students decided to see if they could perform the norm of 45 sit-ups in one minute. The first student did 64 sit-ups, the second did 69, the third did 65, and the fourth did 67. Accurate Precise Both Neither The average score for the 5th-grade math test is 89.5. The top 5th graders took the test and scored 89, 93, 91, and 87. Accurate Precise Both Neither Yesterday the temperature was 89 °F, tomorrow it’s supposed to be 88 °F, and the next day it’s supposed to be 90 °F, even though the average temperature for September is 75 °F. Accurate Precise Both Neither Four friends decided to play horseshoes. They took a picture of their results: Accurate Precise Both Neither A local grocery store held a contest to see who could most closely guess the number of pennies inside a large jar. The first six people guessed the numbers 735, 209, 390, 300, 1005, and 689. The grocery clerk said the jar actually contains 568 pennies. Accurate Precise Both Neither Exercise 5: Significant Digits And Scientific Notation Part 1 Determine the number of significant digits in each number, and write the specific significant digits. 405000 0.0098 39.999999 13.00 80,000,089 55,430.00 0.000033 620.03080 Part 2 Convert each number into scientific notation. 70,000,000,000 0.000000048 67,890,000 70,500 450,900,800 0.009045 0.023 Exercise 6: Percentage Error Determine the percentage error in each scenario. Show your work on all problems. A dad holds five coins in his hand. He tells his son that if he can guess the amount of money he is holding within 5% error, he can have the money. The son guesses that dad is holding 81 cents. The dad opens his hand and displays 90 cents. Did the son guess close enough to get the money? A science teacher tells her class that their final project requires students to measure a specific variable and determine the velocity of a car with no more than 2.5% error. Jennifer and Johnny work hard and decide the velocity of the car is 34.87 m/s. The teacher informs them that the actual velocity is 34.15 m/s. Will Jennifer and Johnny pass their final project? A train is on its way from Chicago, IL to Madison, WI. The trip is said to last 3.15 hours. When the train arrives in Madison, the conductor notices the trip took 3.26 hours. The train company prides itself on always having its trains arrive within a 3% error of the expected time. Will the train company live up to its reputation on this trip? A coach tells his Little League players that hitting a 0.275 batting average, within 7% error, means that they had a really great season. Seven-year-old Tommy ended the season with a 0.258 batting average. According to his coach, did Tommy have a great season? Exercise 7: Experimental Variables Determine the variables tested in each of the following experiments. If applicable, determine and identify any positive or negative controls. A study is being done to test the effects of habitat space on the size of fish populations. Different sized aquariums are set up with six goldfish in each one. Over a period of six months, the fish are fed the same type and amount of food. The aquariums are equally maintained and cleaned throughout the experiment. The temperature of the water is kept constant. At the end of the experiment, the number of surviving fish are surveyed. A. Independent Variable: B. Dependent Variable: C. Controls: To determine if the type of agar affects bacterial growth, a scientist cultures E. coli on four different types of agar. Five petri dishes are set up to collect results: • One with nutrient agar and E. coli • One with mannitol-salt agar and E. coli • One with MacConkey agar and E. coli • One with LB agar and E. coli • One with nutrient agar but NO E. coli A. Independent Variable: B. Dependent Variable: C. Controls: