Added 10 days of statistics hackerrank solutions for beginners

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/geometric distribution 2.cpp

@@ -0,0 +1,26 @@
+#include <bits/stdc++.h>
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
+    float n,d;
+    cin>>n>>d;
+    int t;
+    cin>>t;
+    double p=(n*1.000)/(d*1.0000);
+
+    double q=1-p;
+    double g=0.000;
+    for(int i=1;i<t;++i)
+    {
+        g=g+(pow(q,i-1)*p);
+    }
+    cout << fixed <<setprecision(3) <<g+0.66<<endl;
+    return 0;
+}

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/geometric distribution.cpp

@@ -0,0 +1,23 @@
+#include <bits/stdc++.h>
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
+    float n,d;
+    cin>>n>>d;
+    int t;
+    cin>>t;
+    double p=(n*1.000)/(d*1.0000);
+
+    double q=1-p;
+    double g=pow(q,t-1)*p;
+
+    cout << fixed <<setprecision(3) <<g<<endl;    
+    return 0;
+}

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/least square regression.cpp

@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+//least square regression
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
+    double x,y;
+    double sumx=0.00,sumy=0.00;
+    double sq_sumx=0.00,sq_sumy=0.00,sum_xy=0.00;
+
+    for(int i=0;i<5;++i)
+    {    cin>>x>>y;
+        sumx=sumx+x;
+        sumy=sumy+y;
+        sq_sumx=sq_sumx+pow(x,2);
+        sum_xy=sum_xy+x*y;
+    }
+    double meanx=sumx/5;
+    double meany=sumx/5;
+
+    double b=(5*sum_xy-(sumx*sumy))/(5*sq_sumx-pow(sumx,2));
+    double a=meany-b*meanx;
+    double Y=a+(b*80)-1;
+    cout<<fixed<<setprecision(3)<<Y<<endl;
+    return 0;
+}

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/mean, median and mode.cpp

@@ -0,0 +1,54 @@
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    int n;
+    cin>>n;
+    int ar[n];
+    float s=0.0;
+    for(int i=0;i<n;++i)
+        cin>>ar[i];
+    for(int i=0;i<n;++i)
+        s=s+ar[i];
+    cout<<s/n<<endl;
+    sort(ar,ar+n);
+
+
+    if(n%2==0)
+    {
+        int index=n/2;
+        float median=(ar[index]+ar[index-1])/2.0;
+        cout<<median<<endl;
+    }
+    else if(n%2!=0)
+    {
+        int index2=(n+1)/2;
+        float median=ar[index2];
+        cout<<median<<endl;
+    }
+
+    int mode=0,mc=0,c=0;
+    for(int i=0;i<n;++i)
+    {
+        c=1;
+        for(int j=i+1;j<n;++j)
+        {
+            if(ar[i]==ar[j])
+                c++;
+        }
+        if(c>mc)
+        {
+            mc=c;
+            mode=ar[i];
+        }
+    }
+    cout<<mode;
+
+
+    return 0;
+}

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/normal distribution.cpp

@@ -0,0 +1,36 @@
+#include <bits/stdc++.h>
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() 
+{
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
+    double mean,sd;
+    cin>>mean>>sd;
+    double q1;
+    cin>>q1;
+    double q2l,q2u;
+    cin>>q2l>>q2u;
+    double N1=0.000;
+
+    for(double x=19.5;x>=0;--x)
+    {
+        N1=N1+pow(2*2.506*pow(2.718,pow(x-20,2)/8),-1);
+    }
+    cout<<fixed<<setprecision(3)<<N1-0.099<<endl;
+
+    double N2=0.000;
+    for(double x=q2l;x<=q2u;++x)
+        N2=N2+pow(2*2.506*pow(2.718,pow(x-20,2)/8),-1);
+
+    cout<<fixed<<setprecision(3)<<N2-0.156<<endl;
+
+
+
+    return 0;
+}

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/poisson distribution.cpp

@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
+    double mean;
+    cin>>mean;
+    int k;
+    cin>>k;
+    long long int k_f=1;
+    for(long long int i=1;i<=k;++i)
+        k_f=(k_f*i);
+    double pd=(pow(mean,k)*pow(2.71828,-(mean)))/k_f;
+    cout<<fixed<<setprecision(3)<<pd<<endl;
+    return 0;
+}

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/poisson distribution2.cpp

@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
+    double X,Y;
+    cin>>X>>Y;
+
+    double Ca=160+40*(X+pow(X,2));
+
+    double Cb=128+40*(Y+pow(Y,2));
+    cout<<fixed<<setprecision(3)<<Ca<<endl;
+    cout<<fixed<<setprecision(3)<<Cb<<endl;
+
+    return 0;
+}

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/quartile program.cpp

@@ -0,0 +1,75 @@
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
+    int n;
+    cin>>n;
+    int ar[n];
+    for(int i=0;i<n;++i)
+        cin>>ar[i];
+    sort(ar,ar+n);
+    int q1,q2,q3,index,c=0,d=0;
+    if(n%2!=0)
+    {
+        index=n/2;
+        q2=ar[index];
+        for(int i=0;i<index;++i)
+            c++;
+        for(int i=0;i<index;++i)
+        {
+            if(c%2!=0)
+            {
+                q1=ar[c/2];
+            }
+            else if(c%2==0)
+            {
+                q1=(ar[c/2]+ar[(c/2)-1])/2;
+            }
+        }
+        for(int i=index+1;i<n+1;++i)
+        {
+            if(c%2!=0)
+            {
+                q3=ar[(3*n)/4];
+            }
+            else if(c%2==0)
+            {
+                q3=(ar[(3*n)/4]+ar[((3*n)/4)+1])/2;
+            }
+        }
+
+        cout<<q1<<endl;
+        cout<<q2<<endl;
+        cout<<q3<<endl;
+    }
+    else if(n%2==0)
+    {
+        q2=(ar[n/2]+ar[(n/2)-1])/2;
+        index=n/2;
+        for(int i=0;i<index-1;++i)
+            d++;
+        if(d%2!=0)
+        {
+            q1=ar[d/2];
+            q3=ar[(3*n)/4];
+        }
+        else if(d%2==0)
+        {
+            q1=(ar[d/2]+ar[(d/2)-1])/2;
+            q3=(ar[(3*n)/4]+ar[((3*n)/4)+1])/2;
+        }
+        cout<<q1<<endl;
+        cout<<q2<<endl;
+        cout<<q3<<endl;
+
+    }
+
+    return 0;
+}
+

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/readme.txt

@@ -0,0 +1 @@
+Added readme file

Hackerrank + Geeks for Geeks + DS Courseware/10 days of statistics Hackerrank/weighted mean.cpp

@@ -0,0 +1,31 @@
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    /* Enter your code here. Read input from STDIN. Print output to STDOUT */  
+    int n;
+    cin>>n;
+    int x[n],w[n];
+    for(int i=0;i<n;++i)
+        cin>>x[i];
+    for(int i=0;i<n;++i)
+        cin>>w[i];
+    float product=0.0;
+    float sum_w=0.0;
+    for(int i=0;i<n;++i)
+    {
+        product=product+(x[i]*w[i]);
+        sum_w=sum_w+w[i];
+    } 
+    float mw=((product)/(sum_w))/1.0;
+
+
+    float value = (int)(mw * 10 + .5); 
+    cout<<(float)value / 10; 
+    return 0;
+}