(1 point)
Is
>> a = zeros( 5 , 5 );
the same as
>> a=zeros(5,5);
(yes or no)?
(1 point)
Is
>> a = [10];
the same as
>> a = 10;
(yes or no)
(1 point)
Does
>> plot([1,2,3])
produce the same graph as
>> plot(1:3)
(yes or no)
(5 points)
Suppose you have loaded observed daily climate data into a matrix Data in
Matlab. There is one row for each day, and the columns contain:
First column of D – Year of observation
Second column of D – Month of observation
Third column of D – Day of observation
Forth column of D – Daily precipitation (mm)
Finish the following lines of code to create a logical matrix R for rows of D with
observations:
a) in the year 1990?
R = D(:,1)
b) any year up-to-and-including 1990?
R = D(
c) in month of December?
R=
d) in either December or January or February?
R=
e) in the month of January in the 1990?
R=
(2 points)
Suppose you have a matrix P with 12 rows and 30 columns. The data in each row
are for the same month, and data in each column are for the same year:
P=
P for Jan
1961
P for Feb
1961
P for Mar
1961
…
P for Jan
1962
P for Feb
1962
P for Mar
1962
P for Jan
1963
P for Feb
1963
P for Mar
1963
…
…
…
How could you calculate the means for each month? (assume no NaNs)
(2 points)
Given the two histograms for Distributions A and B, which ONE of the following
is true?
a)
b)
c)
d)
A and B have same mean, A has highest standard deviation
A and B have same mean, B has highest standard deviation
A and B have same mode, A has highest standard deviation
A and B have same mode, B has highest standard deviation
(3 points)
Match the mean, median and trimmed mean with their definitions:
1. The mean
a) the middle value when observations are ordered from
smallest to largest.
2. The median
b) sum all values, then divide by the number of values.
3. The trimmedmean
c) Discard a percentage of the outlying values before
calculating the arithmetic average.
(3 points)
For each of the following distributions, state whether the mean is
 greater than the median,
 equal to the median, or
 less than the median.
(2 points)
Given the following cumulative frequency distribution plot of observed
temperature, which ONE of the following statements is true?
a)
b)
c)
d)
half of all the observations are greater than 23C?
the mean is 23C?
probability of a value being exactly 23C is 50%?
the data are positively skewed?
(4 points)
Match each histogram with the boxplot that represents the same dataset: