Determine the variables tested in the each of the following experiments. If applicable, determine and identify any positive or negative controls.nn nnObservationsnn1. 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 is surveyed.nnA. Independent Variable:nn nn nnB. Dependent Variable:nn nn nnC. Controlled Variables/Constants:nn nn nnD. Experimental Controls/Control Groups:nn nn nn2. 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:nn§ One with nutrient agar and E. colinn§ One with mannitol-salt agar and E. colinn nn§ One with MacConkey agar and E. colinn§ One with LB agar and E. colinn§ One with nutrient agar but NO E. colinn nnAll of the petri dishes received the same volume of agar, and were the same shape and size. During the experiment, the temperature at which the petri dishes were stored, and at the air quality remained the same. After one week the amount of bacterial growth was measured.nnA. Independent Variable:nn nn nnB. Dependent Variable:nn nnC. Controlled Variables/Constants:nn nn nnD. Experimental Controls/Control Groups:nn
Exercise 3: Testable ObservationsnnDetermine which of the following observations are testable. For those that are testable:nnDetermine if the observation is qualitative or quantitativennWrite a hypothesis and null hypothesisnnWhat would be your experimental approach?nnWhat are the dependent and independent variables?nnWhat are your controls – both positive and negative?nnHow will you collect your data?nnHow will you present your data (charts, graphs, types)?nnHow will you analyze your data?nn nnObservationsnn1. A plant grows three inches faster per day when placed on a window sill than it does when placed on a on a coffee table in the middle of the living room.nn nn nn2. The teller at the bank with brown hair and brown eyes is taller than the other tellers.nn nn nn nn3. When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she does not exercise and eats fatty foods.nn nn nn nn4. The Italian restaurant across the street closes at 9 pm but the one two blocks away closes at 10 pm.nn nn nn5. For the past two days, the clouds have come out at 3 pm and it has started raining at 3:15 pm.nn nn nn nn6. George did not sleep at all the night following the start of daylight savings.nn nn nn nnExercise 4: ConversionnnFor each of the following, convert each value into the designated units.nn nn nn1. 46,756,790 mg = _______ kgnn nn nn2. 5.6 hours = ________ secondsnn nn nn3. 13.5 cm = ________ inchesnn nn nn4. 47 °C = _______ °Fnn nn nn nn nnExercise 5: Accuracy vs. PrecisionnnFor the following, determine whether the information is accurate, precise, both or neither.nn nn1. During gym class, four students decided to see if they could beat the norm of 45 sit-ups in a minute. The first student did 64 sit-ups, the second did 69, the third did 65, and the fourth did 67.nn nn nn2. 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.nn nn3. 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 for September is only 75 °F degrees!nn nnnn4. Four friends decided to go out and play horseshoes. They took a picture of their results shown to the right:nn nn nn nn nn5. A local grocery store was holding a contest to see who could most closely guess the number of pennies that they had 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.nn nn nnExercise 6: Significant Digits and Scientific NotationnnPart 1: Determine the number of significant digits in each number and write out the specific significant digits.nn nn1. 405000nn nn nn2. 0.0098nn nn nn3. 39.999999nn nn nn4. 13.00nn nn nn5. 80,000,089nn nn nn6. 55,430.00nn nn nn7. 0.000033nn nn nn8. 620.03080nn nnPart 2: Write the numbers below in scientific notation, incorporating what you know about significant digits.nn nn1. 70,000,000,000nn nn nn2. 0.000000048nn nn nn3. 67,890,000nn nn nn4. 70,500nn nn nn5. 450,900,800nn nn nn6. 0.009045nn nn nn7. 0.023nn
