Victoria Amber Blakeney
Answer the following questions and Email it before 02/07/2015
Exercise 1: Data Interpretation
Dissolved oxygen is oxygen that is trapped in a fluid, such as water. Since many living organism requires oxygen to survive, it is a necessary component of water systems such as streams, lakes and rivers in order to support aquatic life. The dissolved oxygen is measured in units of ppm—or parts per million. Examine the data in Table 4 showing the amount of dissolved oxygen present and the number of fish observed in the body of water from which the sample was taken; finally, 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 |
| |

1. What patterns do you observe based on the information in Table 4? The more dissolved oxygen in the water, the more fish are observed in that area of water.

2. 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. If there is more dissolved oxygen in the water, there will be more fish present in the area the water sample is taken from.

3. What would your experimental approach be to test this hypothesis? I would test the dissolved oxygen in different areas of water, keep track of the fish in those areas and compare the results.

4. What would be the independent and dependent variables? Independent Variable- Dissolved Oxygen Deoendent Oxygen- Fish

5. What would be your control? Control: Aquarium. Measuring dissolved oxygen level and repeating measurement every time an observation of number of fish is made.

6. What type of graph would be appropriate for this data set? Why? A line graph will be appropriate because it will support the hypothesis and will provide clear results.

7. Graph the data from Table 4: Water Quality vs. Fish Population table (found at the beginning of this experiment).[pic] 8. Interpret the data from the graph made in Question 7. The graph above shows the fish population on the Y axis and the dissolved oxygen on the X axis. The fish population increases in the above graph due to more dissolved oxygen that is found in the body of water. When concentration is higher than 12 (ppm), the relationship is less clear.
Exercise 2: Testable Observations
Determine which of the following observations are testable. For those that are testable:

• Determine if the observation is qualitative or quantitative

• Write a hypothesis and 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 (charts, graphs, types)?

• How will you analyze your data?

1. 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. Qua Hypothesis: If a plant is placed on a window sill, it will grow faster than a plant placed on a coffee table in the middle of the living room. Null Hypothesis: Increased light does not make plants grow faster. Approach: Place two plants in window. Leave one in the window and take second plant and let it spend different amounts of time in the light (decreased light exposure). Dependent Variable: Height of plant. Independent Variable: Amount of time spent in the sunlight by each plant. Control: Plant remaining out of direct sunlight (but not in total darkness). Data collection: Measure height of each plant every day for a week and record the total growth after one week. Data presentation: Use a bar graph to show the results. Each of the three plants will have its own bar representing the height it grew in one week. Analyze: Look for an increase in growth with increased time on window sill.

2. The teller at the bank with brown hair and brown eyes is taller than the other tellers. No testable hypothesis. This is an observation.

3. 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. Qua Hypothesis: If Sally eats healthy food it will lead to lower blood pressure. Null Hypothesis: A healthy diet doesn’t lead to lower blood pressure. Approach: Collect blood pressure data over time for groups eating healthy foods and a group that eats fatty foods. Independent Variable: Healthy or Unhealthy Diet Dependent Variable: Blood pressure Controls: All groups should be exposed to similar amount of exercise and stress. Data collection: Test the blood pressure of your study subjects at fixed times over time, always at the same time of day and under similar diet conditions. Presentation: Use a line graph for individual evaluation over time. Use a bar graph to show the average blood pressure for each of your study groups.

4. The Italian restaurant across the street closes at 9 pm but the one two blocks away closes at 10 pm. No testable hypothesis. This is a statement with no testable relationships.

5. For the past two days, the clouds have come out at 3 pm and it has started raining at 3:15 pm. No testable hypothesis. This is an observation and could not create a controlled experiment.

6. George did not sleep at all the night following the start of daylight savings. Qua Hypothesis: If daylight savings started, George will not sleep. Null Hypothesis: Daylight savings did not affect how much George was able to sleep. Approach: Study George’s sleeping habits before, during, and after daylight savings time. Dependent Variable: The number of hours George sleeps during daylight savings time. Independent Variable: The day/time. Control: George’s average night’s sleep. Data collection: Record George’s sleeping patterns for several weeks before, during, and after daylight savings time. Write down what time he goes to bed and how many hours he sleeps for each night. Presentation: Use a line graph to plot the day/time on the x axis and George’s hours of sleep on the y axis. Analyze: Use the data to show whether daylight savings time affected George’s sleep.
Exercise 3: Conversion
For each of the following, convert each value into the designated units.

1. 46,756,790 mg = _46.756790 kg 2. 5.6 hours = _20,160__ seconds 3. 13.5 cm = _5.31_ inches 4. 47 °C = _116_ °F
Exercise 4: Accuracy and Precision
For the following, determine whether the information is accurate, precise, both or neither.

1. 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. Accurate

2. The average score for the 5th grade math test is 89.5. The top 4th graders took the test and scored 89, 93, 91 and 87. Precise

3. 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! Neither

4. Four friends decided to go out and play horseshoes. They took a picture of their results shown to the right: Accurate

5. 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. Neither

Exercise 5: Significant Digits and Scientific Notation
Part 1: Determine the number of significant digits in each number and write out the specific significant digits.

1. 405000- 3 (405) 2. 0.00980-2 (98) 3. 39.999999- 8 (39999999) 4. 13.00- 4 (1300) 5. 80,000,089- 8 (80000089) 6. 55,430.00- 7 (5543000) 7. 0.000033- 2 (33) 8. 620.03080-8 (62003080)

Part 2: Write the numbers below in scientific notation, incorporating what you know about significant digits.

1. 70,000,000,000- 7x1010 2. 0.000000048-4.8x10-8 3. 67,890,000- 6.789x107 4. 70,500- 7.05x104 5. 450,900,800- 4.509008x108 6. 0.009045- 9.045x10-3 7. 0.023- 2.3x10-2

Exercise 6: Percentage Error
In the questions below, determine the percentage error. Show your work on all problems.

1. 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 he is holding 81 cents. The dad opens his hand and displays 90 cents. Did the son guess close enough to receive the money from his father?
No
81-90/90*100= 10%

2. A science teacher tells her class that their final project requires the 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?
Yes
34.87-34.15/34.15*100=2.1%

3. A locomotive 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 it actually took them 3.26 hours. The train company prides itself on always having its trains to the station within a 3% error of the expected time. Will the train company live up to its reputation on this trip?
Yes
3.15-3.26/3.26*100=3.4%

4. A coach tells his little league players that hitting a .275 batting average, within 7% percentage error, means that they had a really great season. Seven year old Tommy ended the season hitting a .258 batting average. According to his coach, did he have a great season?
Yes
0.275-0.258/0.258*100=6.6%