You may load the data into MATLAB with the command load toxic.csv. The data will

Question

You may load the data into MATLAB with the command load toxic.csv. The data will then be in an array called toxic. The column information represents:

Column 1: Year AD

Column 2: Cadmium (nanograms per gram)

Column 3: Lead (nanograms per gram)

Column 4: Thallium (nanograms per gram)

ALLOWED SYNTAX: Complete the following (1) WITHthe use of for loopsand conditional blocks[i.e. if-elseif...else-end]; (2) you may NOT use any syntax requiring the dot operator; (3) you may use relational operators on scalars but you may NOTuse them on arrays. (Relational operatorsinclude: <, >, <=, >=, ==, ~=) (4) You may reuse theyears that were found using the find function in Section 1.

1.How many years during the period of this data set have a lead concentration greater than 0.2 ng/g?

2.For what percentage of the years during the 1800s (1800-1899) is the lead concentration greater than 0.01 ng/g?

3.What is the most recent year during which lead is greater than 100times the concentration of cadmium?Whatis the concentration of Pb that year?

4.For which year during the 1900s (1900-1999) did cadmium contribute its largest fraction to the total heavy metal concentration (i.e., year with largest Cd/(Pb+Cd+Th))?What is that value?(hint: help max)

5.[Up to 2pt bonus]During which decades (i.e, 1900-1909, 1910-1919, etc.) of the 1900s did lead concentration exceed 0.3 (ng/g)?

Explanation / Answer

%without data it is hard to find out errors, so if any answer is wrong, mention it in the comments

d=load('toxic.csv');
[r,c]=size(d);
%1
a=0;
for i=1:r
if d(i,3)>.2
a=a+1;%a holds answer to first question
end
end
%2
y=0;
for i=1:r
if d(i,1)>=1800 && d(i,1)<=1899
if d(i,3)>.01
y=y+1;
end
end
end
%y is the percentage(since there are 100 years spanned in 1800 to 1899)
%3
yLead=0;%these variables hold answers for 3rd part
year=0;
for i=r:-1:1
if d(i,3)>100*d(i,2)
yLead=d(i,3);
year=d(i,1);
break;
end
end
%4
m=0;
yCd=0;%this variable holds the year for which cntribution is highest
for i=1:r
if d(i,1)>=1900 && d(i,1)<=1999
conc=d(i,2)/(d(i,2)+d(i,3)+d(i,2));
if conc>m
yCd=d(i,1);
m=conc;
  
end
end
end
%5
dec=zeros(1,10);
k=0;
for i=1:r
if d(i,1)>=1900 && d(i,1)<=1999
  
if d(i,3)>.3
dec(floor(k/10)+1)=1;
end
k=k+1;
end
end
decades=zeros(10,2);%this array holds the deacdes in 2 columns
l=1;
for i=1:10
if dec(i)==1
decades(l,1)=1900*i+10*i;
decades(l,2)=decades(l,1)+9;
l=l+1;
end
end

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