StatisticsResearch in EcologyMaya Damski

Atlantic Sharp-nose sharksMales Females

920 840928 850935 932943 960950 960950 965954 972960 980962 980974 985975 995975 1000952 1000950 1009

1010101010101020102510251028103010381043105410601160

Mean: Mean:950 998

Median: Median:952 1009

Mode: Mode:950, 975 1010

920 930 940 950 960 970 980 990 1000

Average Length of Sharp-nose Sharks

Sea Turtles

Color Survived Hatchlings

Blue 13 25

Yellow 25 25

Green 18 25

Red 3 25

Orange 4 25

Blue Yellow Green Red Orange0

5

10

15

20

25

Number of Sea Turtle Hatchlings in Group Site F

Survived Hatchlings

Bottle Cap Colors on the Beach

15%7%

5%

21%12%

1%

11%

18% 7%3%

Percentage of Bottle Cap Colors

RedOrangeYellowBlueGreenPurpleBlackWhiteClearOther

Color NumberRed 11Orange 5Yellow 4Blue 15Green 9Purple 1Black 8White 13Clear 5Other 2

Bottle caps are not only the garbage that is washed up on beaches. Some examples include plastic bags and lumber. The litter affects animals, and sometimes kills them.

Frequency Distribution of Sea Cigars by Size (cm)

"1-5" "6-10"

"11-15"

"16-20"

"21-25"

"26-30"

02468

1012

Frequency Distribution of Sea Cigars

Size Class

Freq

uenc

y

Size # of Sea(in cm) Cigars"1-5" 0"6-10" 3"11-15" 4"16-20" 12"21-25" 5"26-30" 1

Probability

Coral Planula Survival Probability

Probability

Type

s of C

oral

Trial # Water Substrate Wave

Survived?

  Temp. / Depth ActionYes or No

1 3 3 4Yes2 6 6 3No3 4 5 1No4 4 1 6Yes5 3 1 3No6 6 3 4No7 5 5 6No8 1 6 3No9 1 4 3No

10 5 6 3No11 1 2 6No12 1 5 6No13 6 3 3No14 1 2 2No15 5 3 4Yes16 3 2 3No17 5 6 1No18 5 6 4No

VarianceVariance is one of the two ways to describe how far away your data is from the mean.

This formula is the way to calculate variance.

the sum = the mean of the data

X = each data value n = the number of values

Standard Deviation

Standard Deviation also shows how spread out the data are.

Theoretical Distribution Curve

1 3 5 7 9 11 13 15 17 19 21 23 250

0.51

1.52

2.53

3.54

Sample Distribution of Sea Cigar Lengths

Length (cm)

Freq

uenc

y0 1 2 3 4 5 6 7 8 9 10

0

0.5

1

1.5

2

2.5

3

TDC of 25 Mangrove Seedlings

Length of Seedling (cm)

Freq

uenc

y

Size Frequency6 0.38 0.8

10 1.512 2.214 2.516 2.218 1.520 0.822 0.3

Theoretical Distribution Curve (TDC) is an ideal picture of a distribution based upon random sampling.

T-TestControl Treatment

14 1413 1313 1513 1513 1513 14

14 14 15 15

P= 0.000545057

p

The t-test equation tests if there is a significant difference between the means of two independent samples. The t-test is calculated by the t- statistic. The formula for the t – statistic is on the bottom of this slide.Key

X1=mean of the first groupX2=mean of the second groupn1=number of _ in the first groupn2 =number of _ in the second group