2.2 CH 1-3 Statistics, Samples, Displaying & Describing Data.

Calculate the Standard Deviation for the following data which was sampled from a large population: 4,10,12,2,15,5

5.10

The following lengths were obtained from a sample of a population of Wild Grape Vine in a forest in Virginia: 8.3m, 8.1m, 7.2m, 7.8m, 7.2m, 8.8m, 8.3m, 7.5m, 8.5m, 8.3m What is the mode of this population?

8.3

The following lengths were obtained from a sample of a population of Poison Ivy vine in a forest in Southwest Virginia: 8.7m, 8.8m, 7.1m, 7.8m, 7m, 8.1m, 8.7m, 8.7m, 8.5m, 8.8m What is the mode of this population?

8.7 ± 0

Choose the box plot that best represents the following data:

B median: 21 Max: 41 1st Q: 18 3rd Q: 33 IQR: 15

These data are displayed using what type of graph? [x] What type of variables are displayed?

bar, categorical

What type of graph is shown in this figure? (bars touching)

histogram

For categorical variables, the [x] is the most important descriptive statistics - measuring the fraction of observations in a given category.

proportion

Researchers have created every possible "knockout" line in yeast. Each line has exactly one gene deleted and all the other genes present (Steinmetz et al. 2002). The growth rate - how fast the number of cells increases per hour - of each of these yeast lines has also been measured, expressed as a multiple of the growth rate of the wild type that has all the genes present. In other words, a growth rate greater than 1 means that a given knockout line grows faster than the wild type, whereas a growth rate less than 1 means it grows more slowly. Below is the growth rate of a random sample of knockout lines: 0.86, 1.02, 1.02, 1.01, 1.02, 1, 0.99, 1.01, 0.91, 0.83, 1.01 What is the variance of growth rate this sample of yeast lines (answer to 6 decimals)?

0.004889 ± 0.01

Researchers have created every possible "knockout" line in yeast. Each line has exactly one gene deleted and all the other genes present (Steinmetz et al. 2002). The growth rate - how fast the number of cells increases per hour - of each of these yeast lines has also been measured, expressed as a multiple of the growth rate of the wild type that has all the genes present. In other words, a growth rate greater than 1 means that a given knockout line grows faster than the wild type, whereas a growth rate less than 1 means it grows more slowly. Below is the growth rate of a random sample of knockout lines: 0.89, 1.02, 0.98, 0.88, 0.78, 0.91, 0.93, 0.73, 1.02, 0.73, 0.73 What is the variance of growth rate this sample of yeast lines (answer to 6 decimals)?

0.011783

Researchers have created every possible "knockout" line in yeast. Each line has exactly one gene deleted and all the other genes present (Steinmetz et al. 2002). The growth rate - how fast the number of cells increases per hour - of each of these yeast lines has also been measured, expressed as a multiple of the growth rate of the wild type that has all the genes present. In other words, a growth rate greater than 1 means that a given knockout line grows faster than the wild type, whereas a growth rate less than 1 means it grows more slowly. Below is the growth rate of a random sample of knockout lines: 1.02, 0.8, 0.9, 0.68, 0.94, 0.94, 1.04, 0.72, 0.98, 1.04, 0.92 What is the standard deviation of growth rate this sample of yeast lines (answer to 3 decimals)?

0.124 ± 0.01

Researchers have created every possible "knockout" line in yeast. Each line has exactly one gene deleted and all the other genes present (Steinmetz et al. 2002). The growth rate - how fast the number of cells increases per hour - of each of these yeast lines has also been measured, expressed as a multiple of the growth rate of the wild type that has all the genes present. In other words, a growth rate greater than 1 means that a given knockout line grows faster than the wild type, whereas a growth rate less than 1 means it grows more slowly. Below is the growth rate of a random sample of knockout lines: 0.79, 0.87, 0.95, 0.78, 1.04, 0.9, 0.95, 0.61, 1.01, 0.61, 0.99 What is the standard deviation of growth rate this sample of yeast lines (answer to 3 decimals)?

0.150

Researchers have created every possible "knockout" line in yeast. Each line has exactly one gene deleted and all the other genes present (Steinmetz et al. 2002). The growth rate - how fast the number of cells increases per hour - of each of these yeast lines has also been measured, expressed as a multiple of the growth rate of the wild type that has all the genes present. In other words, a growth rate greater than 1 means that a given knockout line grows faster than the wild type, whereas a growth rate less than 1 means it grows more slowly. Below is the growth rate of a random sample of knockout lines: 0.65, 0.73, 0.94, 0.8, 0.61, 0.68, 0.75, 0.83, 1.03, 1.04, 0.66 What is the mean growth rate of this sample of yeast lines (answer to 2 decimals)?

0.79 ± 0.01

A researcher measured the height of 5 plants and found the following heights; 36cm, 38cm, 18cm, 30cm and 25cm. What is the mean height of this group of plants?

29.4

The average age of piñon pine trees in the coast ranges of California was investigated by placing 500 ten-hectare plots randomly on a distribution map of the psecies in California using a computer. Researchers then found the location of each random plot in the field, and then they measured the age of every piñon pine tree within each of the 10-hectare plots. The average age within the plot was used as the unit measurement. These unit measurements were then used to estimate the average age of California piñon pines. What is the population of interest in this study? _______

all piñon pine trees in California

Dr Eberhardt has been conducting a study in which he wants to know how much glucose is generated by blue-green algae when they are placed under blue light for 4 hours. There are two methods that he can used to determine glucose levels and he needs to know which one is more accurate. In method 1, a hexokinase activity assay is used and the mean of 10 algal samples is 120 mmol, with a standard deviation of 4.8 In method 2, a glucose oxidase activity assay is used and the mean of the same 10 algal samples is 100 mmol, the standard deviation is 4. Which method is more accurate?

both are equally accurate based on their coefficients of variation Method 1: 4.8/120=.04% Method 2: 4/100=.04% This indicates that while the means and standard deviations are different the variability in the two data sets is the same.

A eunuch is a castrated human male. Eunuchs were often used as servants and guards in harems in Asia and the Middle East. In males of some mammal species, castration increases life span. Do male eunuchs also have long lives compared to other men? The accompanying graph shows data on life spans of 81 male eunuchs from the Korean Chosun Dynasty between about 1400 and 1900, according to historical records. These data are compared with life spans of non-eunuch males who lived at the same time, and who belonged to families of similar social sttus (n=1126, 1414, and 49 for the three families shown). Modified from Min et al. (2012), with permission. What type of graph is this? [a] The upper margins of the boxes indicate the [b] quartiles, whereas the lower margins represent the [c] quartiles. Which male group had the highest median longevity? [d] They probably also had the highest mean longevity, because the mean and median are expected to be similar when the distributions are [e], as seems to be the case according to the graph.

box plot, third, first, Eunuch, symmetric

Dr Allistar is interested in studying the frequency of frog mating calls in ponds in Richmond Virginia in the spring. He selects six ponds in the area and sends out his intrepid graduate students to collect the data. What type of sampling method is Dr. Allistar employing in this study?

cluster sampling

Swordfish have a unique "heater organ" that maintains elevated eye and brain temperatures when hunting in deep, cold water. The following graph illustrates the results of a study by Fritsches et al. (2005) that measured how the ability of swordfish retinas to detect rapid motion, measured by the flicker fusion frequency, changes with eye temperature. Is the flicker fusion frequency variable continuous or discrete? [a] Is it categorical or numeric? [b] Is the eye temperature variable continuous or discrete? [c] Is it categorical or numeric? [d] What type of graph is this? [e] Is the relationship positive or negative? [f] Is it linear or nonlinear? [g] The 20 points on the graph were obtained from measurements of six swordfish - each fish was measured several times and the multiple measurements were all combined. Do these samples represent a random sample? [h]

continuous, numeric, continuous, numeric, scatter plot, positive, nonlinear, no

As the Arctic warms and winters become shorter, hibernation patterns of arctic mammals are expected to change. Sheriff et al. (2011) investigated emergence dates from hibernation of arctic ground squirrels at sites in the Brooks Range of northern Alaska. The measurements shown in the following figure are emergence dates in a sample of male and female ground squirrels at one of their study sites. What type of graph is this? [a] The date at which cumulative frequency reaches 0.50 is the [b]. Which sex has the earliest median emergence date? [c] Which sex has the greater IQR? [d] Which sex has an approximate IQR of 8 days? [e] Which sex has an approximate IQR of 4 days? [f]

cumulative frequency distribution, median, female, female, female, male

Endostatin is a naturally occurring protein in humans and mice that inhibits the growth of blood vessels. O'Reilly et al. (1997) investigated its effects on growth of cancer tumors, whose growth and spread requires blood vessel proliferation. Mice having lung carcinoma tumors were randomly divided into groups that were treated with doses of 0, 2.5, 10, or 20 mg/kg of endostatin injected once daily. They found that higher doses of endostatin led to inhibition of tumor growth. Was this study observational or experimental?

experimental

The Cambridge Study in Delinquent Development was undertaken in north London (U.K.) to investigate the links between criminal behavior in young men and the socioeconomic factors of their upbringing (Farrington 1994). A cohort of 395 boys was followed for about 20 years, starting at the age of 8 or 9. All of the boys attended six schools located near the research office. The following table shows the total number of criminal convictions by the boys between the start and end of the study. Number of Convictions Frequency 0 265 1 49 2 21 3 19 4 10 5 10 6 2 7 2 8 4 9 2 10 1 11 4 12 3 13 1 14 2 Total: 395 What type of table is this? [a] What is the variable presented in this table? [b] How many boys had exactly 2 convictions by the end of the study? [c] What percentage of boys had no conviction? [d] (round to nearest whole percentage - report as percentage, not as fraction) Is this frequency distribution symmetric or skewed? [e] Is it unimodal or bimodal? [f] What is the mode? [g] Are there outliers? [h] (yes or no) Does the sample of boys used in this study represent a random sample of British boys? [i]

frequency table, number of convictions, 21, 67%, skewed, unimodal, 0, no, no

The most important descriptive statistics for numerical data are those measuring the [a] of a frequency distribution and its [b]. The [x] tells us something about the average or typical individual - where the observations are centered. The [y] tells us how variable the measurements are from individual to individual - how widely scattered the observations are around the center.

location, spread, location, spread

When its numbers increase following favorable environmental conditions, the desert locust, Schistocerca gregaria, undergoes a dramatic transformation from a solitary, cryptic form into a gregarious form that swarms by the billions. The transition is triggered by mechanical stimulation - locusts bumping into one another. The accompanying figure shows the results of a laboratory study investigating the degree of gregariousness resulting from mechanical stimulation of different parts of the body (modified from Simpson et al. 2001): What type of graph is displayed? [a] Touching the first segment to the hind leg led to the [b] response. Touching the thorax or distal portions of any of the legs resulted in the [c] response. The explanatory variable is [d]. The response variable is [e]

map, greatest, lowest, mechanical stimulation, gregariousness

What type of data is shown in the table below? categories & number

ordinal

Individuals highly sensitive to rewards tend to experience more food cravings and are more likely to be overweight or develop eating disorders than other people. Beaver et al. (2006) recruited 14 healthy volunteers and scored their reward sensitivity using a questionnaire (they were asked to answer yes or no to questions like: "I'm always willing to try something new if I think it will be fun"). The subjects were then presented with images of appetizing foods (e.g., chocolate cake, pizza) while activity of their frono-striatal-amygdala-midbrain was measured using functional MRI. Reward sensitivity of subjects was fuond to correlate with brain activity in response to the images. The explanatory variable is _____. The response variable is _____.

reward sensitivity, brain activity

Cooley et al. (2009) randomly assigned either of two treatments, naturopathic care (diet counseling, breathing techniques, vitamins, and an herbal medicine) or standardized psychotherapy (psychotherapy with breathing techniques and a placebo added), to 81 individuals having moderate to severe anxiety. Anxiety scores decreased an average of 57% in the naturopathic group and 31% in the psychotherapy group. The explanatory variable is _______ The response variable is ______

the treatment type (naturopathic care vs standardized psychotherapy) the anxiety score

Researchers measured the transpiration rate of corn plants at different temperatures. If they were to graph the data, which variable should be placed on the Y axis. Temp. Transp Rate

transpiration rate

While conducting a study on the growth rates of mice on a copper deficient diet, Dr. Ambrose recorded the following weights in grams of the mice after three weeks on the diet. 6.2, 15.8, 14.2, 3.7, 7.5 What is the standard deviation (s) in this set of samples? (calculate to 2 decimal places)

5.25

The following weights were obtained from a sample of a population of Grey Squirrels in a forest in Pennsylvania: 8.4g, 9.3g, 7.8g, 7.3g, 7.8g, 7.1g, 9g, 7.8g, 7.9g, 8g What is the mode of this population?

7.8

The Maryland Biological Stream Survey used electrofishing to count the number of individuals of each fish species in randomly selected 75-m long segments of streams in Maryland. Here are the numbers of blacknose dace, Rhinichthys atratulus, in streams of the Rock Creek watershed: Stream fish/75m Mill_Creek_1 106 Mill_Creek_2 55 North_Branch_Rock_Creek_1 92 North_Branch_Rock_Creek_2 73 Rock_Creek_1 30 Rock_Creek_2 20 Rock_Creek_3 32 Rock_Creek_4 73 Turkey_Branch 72 What is the variance (s2) for this set of data? (calculate to 2 decimal places)

864.03 ± 0.05

Dr. Jennings has been studying the Paw Paw trees in the James River park system over the last several years. She has collected data on the size of 20 patches of Paw Paw trees as well as the diameters of the trunks of each of the trees in the patches. She suspects that there is a relationship between the size of the patch and the diameter of the trees. If she were to give you her raw data (patch size and tree diameters), what type of graph would you use to help her visualize it and why would you use that type of graph?

A _______ would be the most appropriate graph to use because it allows the comparison of _______ measurements from _______. scatter plot, two, the same sample

The Maryland Biological Stream Survey used electrofishing to count the number of individuals of each fish species in randomly selected 75-m long segments of streams in Maryland. Here are the numbers of blacknose dace, Rhinichthys atratulus, in streams of the Rock Creek watershed: Stream fish/75m Mill_Creek_1 76 Mill_Creek_2 102 North_Branch_Rock_Creek_1 12 North_Branch_Rock_Creek_2 39 Rock_Creek_1 55 Rock_Creek_2 93 Rock_Creek_3 98 Rock_Creek_4 53 Turkey_Branch 102 What is the standard deviation (s) for this set of data?

32.08

A researcher measured the height of 5 plants and found the following heights; 32.3cm, 33.2cm, 35.8cm, 48.1cm and 44.1cm. What is the median height of this group of plants? (calculate to one decimal)

35.8 ± 0.1

A microbiologist is studying the effect of a new antibiotic on the bacteria Staphylococcus aureus. He treats five plates containing 1000 bacteria each with the antibiotic, waits 24hrs and then counts the number of bacteria killed. The data collected are shown in the table below. What is the median of this set of data? 75, 52, 27, 84, 3

52

In a particular species of finches, the trait for orange beaks is determined by allele 'O' and the trait for ivory beaks is determined by allele 'o'. A cross between an orange beak and an ivory beak finch results in five offspring all with pale, ivory orange beaks. Which of the following is quantitative data in the write up above?

number of offspring

The maximum length in feet of several whales is listed below. 46, 53, 33, 53, 79 If the maximum length of the Blue Whale, 98 feet, is added to this list, which of the following statements would be true?

the mean would increase

Crohn's disease is an autoimmune inflammatory disorder. The accompanying table shows medians and IQRs for three response variables in 62 Crohn's disease patients randomly assigned either the immunosuppressant drug azathioprine (n=32) or a placebo (n=30) in a clinical trial. Response variables are measured as change from baseline. The data are from Candy et al. 1995. Which table(s) best follows the principles recommended in the beetle book?

*image*

The Maryland Biological Stream Survey used electrofishing to count the number of individuals of each fish species in randomly selected 75-m long segments of streams in Maryland. Here are the numbers of blacknose dace, Rhinichthys atratulus, in streams of the Rock Creek watershed: Stream fish/75m Mill_Creek_1 92 Mill_Creek_2 62 North_Branch_Rock_Creek_1 60 North_Branch_Rock_Creek_2 41 Rock_Creek_1 18 Rock_Creek_2 82 Rock_Creek_3 94 Rock_Creek_4 15 Turkey_Branch 74 What is the standard deviation (s) for this set of data? (calculate to 2 decimal places)

29.61 ± 0.05

A microbiologist is studying the effect of a new antibiotic on the bacteria Staphylococcus aureus. He treats five plates containing 1000 bacteria each with the antibiotic, waits 24hrs and then counts the number of bacteria killed. The data collected are shown in the table below. What is the mean of this set of data? (round to nearest whole number) 1, 41, 38, 28, 44

30

A researcher measured the height of 5 plants and found the following heights; 25cm, 25cm, 45cm, 11cm and 44cm. What is the mean height of this group of plants?

30.0

A researcher measured the height of 6 plants and found the following heights: 22cm, 21cm, 29cm, 21cm, 43cm and 47cm What is the mean height of this group of plants? (calculate to one decimal point)

30.5

The Maryland Biological Stream Survey used electrofishing to count the number of individuals of each fish species in randomly selected 75-m long segments of streams in Maryland. Here are the numbers of blacknose dace, Rhinichthys atratulus, in streams of the Rock Creek watershed: What is the standard deviation (s) for this set of data? 52, 98, 108, 11, 64, 73, 83, 37, 94

31.43

A researcher measured the height of 5 plants and found the following heights; 30.1cm, 43cm, 35.9cm, 31.6cm and 45.2cm. What is the median height of this group of plants? (calculate to one decimal)

35.9

What is the interquartile range of the following set of data? 1, 9, 13, 21, 24, 33, 36, 44, 50, 55, 61

37

A microbiologist is studying the effect of a new antibiotic on the bacteria Staphylococcus aureus. He treats six plates containing 1000 bacteria each with the antibiotic, waits one week and then counts the number of bacteria killed. The data collected are shown in the table below. What is the mean of this set of data? (round to nearest whole number) Plate # of Dead Bacteria 1 393 2 489 3 242 4 440 5 296 6 389

375

An ecologist is studying species density of PawPaw tree patches in different areas around the city. She records densities at six different locations. The data collected are shown in the table below. What is the mean of this set of data? (calculate to 1 decimal place) 462, 278, 667, 530, 478, 194

434.8

Below, the cumulative frequency plot shows height (in inches) of college basketball players. _____ What is the interquartile range?

6 inches

An ecologist is studying species density of PawPaw tree patches in different areas around the city. She records densities at six different locations. The data collected are shown in the table below. What is the mean of this set of data? (calculate to 1 decimal place) Location PawPaw Density 1 762 2 565 3 741 4 767 5 472 6 942

708.2 ± 0.2

While conducting a study on the growth rates of mice on a copper deficient diet, Dr. Ambrose recorded the following weights in grams of the mice after three weeks on the diet. 8.6, 15.6, 12.3, 8.5, 10.4 What is the variance (s2) in this set of samples? (calculate to 2 decimal places)

8.80 ± 0.05

The Maryland Biological Stream Survey used electrofishing to count the number of individuals of each fish species in randomly selected 75-m long segments of streams in Maryland. Here are the numbers of blacknose dace, Rhinichthys atratulus, in streams of the Rock Creek watershed: What is the range for this set of data? 39, 63, 98, 40, 55, 71, 18, 79, 47

80

bar graph of animals What type of graph is this data presented in?

Bar plot

I am sampling arboreal insect communties within the coastal redwood (Sequoia sempervirens) forests. I come upon an enormous redwood tree as I hike through the forest and decide to sample this particular tree because it is large. This tree represents a random sample of trees in the forest.

False

The following graph displays the net number of species listed under the U.S. Endangered Species Act between 1980 and 2002 (US Fish and Wildlife Service 2001): What type of graph is this? [a] Is it true that the steepness of each line segment tells us the net increase in the number of endangered species added in a given year? [b] The net number of endangered species has been [c] (increasing or decreasing) steadily over time, but has tapered off after the year [d].

Line, yes, increasing, 2000,

Which of the following data sets has a larger standard deviation? Set 1: 15, 23, 28, 32, 57 Set 2: 34, 36, 43, 66, 71

Set 2

Ordinal data can be either discrete or continuous but nominal data is always discrete.

True

The coefficient of variation can be used to compare variation in data sets that are on two different scales.

True

The following graph displays the net number of species listed under the U.S. Endangered Species Act between 1980 and 2002 (US Fish and Wildlife Service 2001): What type of graph is this? Is it true that the steepness of each line segment tells us the net increase in the number of endangered species added in a given year? The net number of endangered species has been _______ (increasing or decreasing) steadily over time, but has tapered off after the year ____.

____, Yes, increasing, 2002

Dr. Jennings wants to know how many different types of deciduous trees are found along the Buttermilk Trail near Reedy Creek in the James River park system. What is the population that she will be studying?

all the deciduous trees on the Buttermilk Trail near Reedy Creek

Tree species. Is this a numerical variable or categorical variable? ______ If numerical, state whether the variable is discrete or continuous; or if categorical, state whether the categories are ordinal (ie, have a natural order) or nominal (do not have a natural order). ______

categorical, nominal

graph of number of students What type of data is shown in this figure?

continuous data on a ratio scale

graph of animal count in area 54 What type of data is shown in the graph above?

data on a nominal scale

discrete or continuous: The number of injuries sustained in a fall is a _____numerical variable.

discrete

When graphing data the [------] variable is shown on the x-axis and the [______] variable is shown on the y-axis

explanatory or independent, response or dependent

Male fireflies of the species Photinus ignitus attract females with pulses of light. Flashes of longer duration seem to attract the most females. During mating, the male transfers a spermatophore to the female. Besides containing sperm, the spermatophore is rich in protein that is distributed by the female to her fertilized eggs. The data below are measurements of spermatophore mass (in mg) of 35 males (Cratsley and Lewis 2003). 0.047 0.037 0.041 0.045 0.039 0.064 0.064 0.065 0.079 0.070 0.066 0.059 0.075 0.079 0.090 0.096 0.066 0.078 0.066 0.066 0.055 0.046 0.056 0.067 0.075 0.048 0.077 0.081 0.066 0.172 0.080 0.078 0.048 0.096 0.097 What type of graph would best depict the frequency distribution?

histogram

Angle of flower orientation relative to position of the sun. Is this a numerical variable or categorical variable? ______ If numerical, state whether the variable is discrete or continuous; or if categorical, state whether the categories are ordinal (ie, have a natural order) or nominal (do not have a natural order). _____

numerical, continuous

Heartbeats per minute of a Tour de France cyclist, averaged over the duration of the race. Is this a numerical variable or categorical variable? ____ If numerical, state whether the variable is discrete or continuous; or if categorical, state whether the categories are ordinal (ie, have a natural order) or nominal (do not have a natural order). _______

numerical, continuous

Researchers sent out a survey to US war veterans that asked a series of questions, including whether individuals surveyed were smokers or nonsmokers (Seltzer et al. 1974). They found that nonsmokers were 27% more likely than smokers to respond to a survey within 30 days (based on the much larger number of smokers and nonsmokers who eventually responded). Hypothetically, if the study had ended after 30 days, what effect would this have on the estimate of the proportion of veterans who smoke? Terminating the study at 30 days would [a] of the estimate. Because [b] are more likely to respond, the estimate will be [c]; the true proportion of smokers would be [d] -estimated. This is a form of [e].

reduce the accuracy, non-smokers, biased, under, volunteer bias

The following data give the photosynthetic capacity of nine individual females of the neotropical tree Ocotea tenera, according to the number of fruits produced in the previous reproductive season (Wheelwright and Logan 2004). The goal of the study was to investigate how reproductive effort in females of these trees impacts subsequent growth and photosynthesis. Number of fruits produced previously Photosynthetic capacity (moles O2/m2/s) 10 13.0 14 11.9 5 11.5 24 10.6 50 11.1 37 9.4 89 9.3 162 9.1 149 7.3 What type of graph would best display the association between these two variables? [a] The number of fruits produced previous is the [b] variable. (explanatory or response) The photosynthetic capacity is the [c] variable. (explanatory or response) Below is a graph of the table and describe the association between the two variables. [d] (positive or negative)

scatter plot, explanatory, response, negative

Which of the following types of graphs are useful to display patterns for continuous data?

scatter plot, histogram, cumulative frequency distribution, box plot

A researcher on the VCU campus wants to know how many viral illnesses students on campus have during their entire freshman year. They select students by stopping every fifth student that passes them when standing outside the student commons. What type of sampling method is this?

simple random sampling

When a biologist is talking about a sample, what are they referring to?

some fraction of a population, items for which data is being collected, something that is used to test a biological hypothesis

Male fireflies of the species Photinus ignitus attract females with pulses of light. Flashes of longer duration seem to attract the most females. During mating, the male transfers a spermatophore to the female. Besides containing sperm, the spermatophore is rich in protein that is distributed by the female to her fertilized eggs. The data below are measurements of spermatophore mass (in mg) of 35 males (Cratsley and Lewis 2003). Use the graph above to answer the following questions: The general shape of the graph in the 0.03-0.10 range is [a]. (symmetrical, asymmetrical) The mode falls in what range? [b] (make sure you give a numeric range, but be as specific as possible given the data on the graph) What is the highest frequency? [c] (numeric value only) What is the lowest frequency? [d] (numeric value only) What term would be used to describe the largest measurement in the frequency distribution? [e] What is the largest measurement? [f] (numeric value only)

symmetrical, 0.06-0.07, 10, 1, outlier, 0.17

What does a standard deviation of 0 indicate?

that the mean, median and mode are all the same that all the data values are the same

Below are summary statistics for WEIGHT and HEIGHT (both ratio variables) of American adults. Notice that these two measures are on different scales. What implications can you draw based on the coefficient of variation from these two data sets? Weight Height Mean 160 pounds 66 inches SD 30 pounds 4 inches

that the weight data is more variable than the height data

For each of the following indicate the type of biological data that it represents.

the blood types of 30 people in the biology major- nominal the temperature of different leaves when exposed to white light-interval the amount of time it takes pillbugs to move 12cm towards a food source-ratio the height of plants grown in natural sunlight-ratio the numbers of different species of trees in a forest-ratio

Which of the following is a correct measure of central tendency for this data set? 11, 27, 29, 35, 37, 39, 40, 42, 45, 47, 49, 49, 52, 52, 56, 64, 67, 70, 81

the mean is 47