Download Statistics

Variance
Standard Deviation
Atlantic Sharp-nose Sharks
Gender of Sharks
Mean Length of Sharp-nose Sharks
Female
Male
920
940
960
980
1000
1020
Length in Millimeters
Mean-The average of your set.
Median-The halfway point of the data set when the
numbers are arranged in ascending order.
Mode- The most repeated number in a data set.
Range-
Turtle Survival-Race to the Sea
20
15
# of
hatchlings
survived
10
5
red
orange
blue
green
0
yellow
# of Turtles
25
Color of Piece
This is the
“Percent
#Observed
Triangle” →
Percent %
Total # in
sample
Sea Turtles
Beach Trash- Bottle Caps
A percent is a comparative calculation used to describe a
number out of a sample of 100. The name per-cent means “for
every 100.”
Measuring Sea Cigars
Mesuring Sea Cigars
30
Length (cm)
25
20
15
10
5
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Number
We measured twentyfive sea cigars. Most of
them were from around 15
cm to about 25 cm Most of
them were large, but some
of them were small.
Probability and Chance of Coral Planula survival
Trial #
Survived?
1 No
2 No
3 No
4 No
5 Yes
6 Yes
7 Yes
Probability of Coral Planula Survival
8 No
9 No
10 Yes
Probability
Probability is a way to
measure the chances that
something will occur in relation to
the possible alternatives. A
simple event is when something
happens once. A compound
event is more than one simple
events. 3 things that affect Coral
Planula is water temperature,
depth, and wave action.
0.5
11 No
0.4
12 Yes
0.3
13 No
0.2
14 Yes
0.1
15 No
16 No
0
Theoratical Probabilty
Observed Probability
17 Yes
18 Yes
Standard Deviation
Standard deviation is
basically the square root
of the variance of a data
set
s=
∑(X−X)²
n−1
KEY
∑= the sum
X= the mean of
the data
X= each data
value
n= the number
values
standard deviation
9
10
12
13
13
15
16
18
19
19
19
20
20
20
20
20
21
21
22
23
23
24
25
26
27
4.813176359
Variance
Two values that are used in statistics
to describe how far away your data are
from the mean are variance and
standard deviation. The variance is
calculated as:
s²=
∑(X-X)²
n-1
KEY
∑= the sum
X= the mean of
the data
X= each data
value
n= the number
values
variance
9
10
12
13
13
15
16
18
19
19
19
20
20
20
20
20
21
21
22
23
23
24
25
26
27
23.16666667
Theoretical Distribution Curve Using Mean and Standard Deviation.
Theoretical Distribution of
Sea Cigar Lengths
3
2.5
1.5
frequency
1
0.5
0
0
5
10
15
20
25
Frequency
Distribution of Sea Cigar Lengths
4
3
Frequency
Size
2
2
1
0
1
3
5
7
9 11 13 15 17 19 21 23
Length (cm)
T-Test
Control
Treatment
14
14
13
13
13
15
13
15
13
15
13
14
14
14
15
15
P=0.000545
P-value must be less than
0.05 in order to reject the
null hypothesis. If the pvalue is greater than 0.05
than we will fail to reject
the null hypothesis.
X1-X2
t= 𝑆𝑝2
1
𝑛1
1
(𝑛 )
2