1.2.7 (a) This situation was an experiment. The researchers applied the treatment.

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1 Assignment 1 Homework Solution 1..1 It appears that the problems with the people s digestive system were psychosomatic. They expected to have health problems when their water was fluoridated so when they thought it was fluoridated, they had issues. 1.. The acupuncturist expects patients to respond better to acupuncture instead of aspirin. He or she is more likely to perceive an improvement in a patient that receiving acupuncture even if the patients from each of the two groups respond to the treatment the same way (a) This situation was an experiment. The researchers applied the treatment. (b) The experiment confounds the two effects. There is the effect of the fertilizer and the effect of location of the garden-the west side. The way the experiment was run; it can not be distinguished what caused the improvement-was it the fertilizer or being on the west side of the garden. (c) The person evaluating the tomatoes for their weight could be blinded as far as knowing which side of the garden, east or west, the tomatoes came from. Double-blinding is not needed since the tomato plants are not consciously aware of what treatment they receive (a) Since the three clinics are three clusters, the sampling is cluster sampling. (b) Simple random sampling (c) Stratified random sampling since the different altitudes are the strata (d) Simple random sampling (e) Stratified random sampling since the three breed sizes are the strata 1.. (a) The sample is not random and it is also not representative of the general population The sample consists of volunteers that are from nightclubs. People that attend nightclubs are less likely to have social anxiety than the rest of the general populace. A better strategy would be to recruit subjects from across the population. (b) Bias occurs because data is only collected on rainy days. Water population in the stream might be lower due to the influx of rainwater; therefore, reducing the concentration of pollutants. A better idea would be to sample the water during a variety of weather conditions. (c) Recording observations only when the random coordinates are within a tree canopy could cause bias. First trees with larger canopies are more likely to be chosen over trees with a smaller canopy size. Since canopy size is related to the diameter of the tree, smaller trees would be less likely to be chosen. The bias would be in favor of larger trees. There are a few ways to decrease the likelihood of bias. First, the experimenter could measure the tree closest to the randomly chosen coordinates. Second, the experimenter could number all of the trees in a region, and then use a random number method to determine which trees to measure. Geographical regions be divided into clusters, clusters numbers could be assigned, and then every tree in a designated cluster could be measured. (d) Fish caught in one boat in a one day time frame is not a random sample. First, if the area has not been fished recently, then it is more likely to have larger fish. To avoid these types of issues, randomly selected fishing boats could be chosen on randomly selected days.

2 Number of specimens.1.1 (a) i) The variable in the study is the molar width. ii) This variable is continuous iii)the observational unit is the molar, and iv) There are specimens being studied. (b) i) The birth weight, date of birth and the mother s race are the variables in the study. ii) The birth weight and date of birth are continuous. The mother s race is categorical iii) The observational units are the babies. iv) 5 babies were studied..1. (a) i) The variables being studied are height and weight. ii)the height and weight are continuous. iii) The children are the observational units iv) 7 children were studied. (b) i) The variables being studied are blood type and cholesterol. ii) The blood type is categorical and the cholesterol level is continuous. iii) The blood donors are the observational units. iv) 19 donors were studied...1 a. Width measurements on the upper molar of the extinct mammal Width of the Last Upper Molar in mm Number of specimens with this width (b) 1 10 Last Upper Molar width measurements of the Acropithecus Molar Size in mm The shape is bell-shaped; therefore, it is symmetrical

3 Number of dogs..4 Number of Dendritic Branch segments Emanating from a Nerve Cell of a Newborn Guinea Pig Number of Branches..7 a. Glucose Concentration in the Anterior Chamber of the right eye and blood serum of Healthy Dogs Glucose Concentration Number of dogs with this concentration (b) 15 Anterior Chamber Glucose Measurements as % of Blood Glucose for 1 Healthy Dogs Anterior Chamber Glucose Measurements as a % of Blood Glucose

4 Number of Aliquots Assignment..7 y.49 lbs and the median =. lbs..8 Yes, the calculated mean and median are consistent with the claim that in general steers gain.5 lb/day since this value is near the center of the sample data. However, the data is not consistent with the claim that in general the steers gain 4 lbs/day since both the sample mean and median are significantly less than One way to show the data would be as follows: Resistant Bacteria Number of Aliquots Total 10 The histogram corresponding to this data would be Number of Bacteria in Aliquots Resistant to Certain Viruses 5 4 y~ y Number of Resistent Bacteria (b) y 1.7, median 15

5 ..11 The median is the 18.5 position so it is the average of the 18 th and 19 th values. 18 th value is 10 and the 19 th value is 11 so the median is 10.5 piglets The average number of piglets y 10.4 piglets.4.1 (a) The median is 15, Q1 14, Q 0 (b) IQR Q Q (c) If an observation is greater than the value for the Upper Lim then it is considered an outlier. From this data UL Q 1.5 IQR UL 0 1.5* UL 9 bacteria.4. (a) the median is 9., Q 7.4 and Q (b) IQR Q Q UL Q (c) UL IQR UL 18.5 MAO (d) MAO Levels in Schizophrenic Patients Nnmoles behzyladehyde product per 108 platelets