# 14. C PROGRAMMING LAB | Check Now

C PROGRAMMING LAB –14] Develop a program using pointers to compute the sum, mean, and standard deviation of all elements stored in an array of n real numbers.

## C PROGRAMMING -Algorithm

• Step-1: Start
• Step-3: For every value of n read the x
• Step-4: Initialize sum=0 and i=0
• Step-5: For every value of n and i, comuter sum using sum = sum + (*(x+i) – mean) * ( * ( x+i) – mean)
• Step-6: Using the sum value computer variance = sum / n and deviation = sqrt ( variance )
• Step-7: Display mean, variance, deviation
• Step-8: Stop

## Program -14 source code

```#include<stdio.h>
#include<math.h>
int main()
{
int n , i;
float x[20],sum,mean;
float variance , deviation;
printf("Enter the value of n \n");
scanf("%d",&n);
printf("enter %d real values \n",n);
for (i=0;i<n;i++)
{
scanf("%f",(x+i));
}
sum=0;
for(i=0;i<n;i++)
{
sum= sum+*(x+i);
}
printf("sum=%f\n",sum);
mean=sum/n;
sum=0;
for(i=0;i<n;i++)
{
sum=sum+(*(x+i)-mean)*(*(x+i)-mean);
}
variance=sum/n;
deviation=sqrt(variance);
printf("mean(Average)=%f\n",mean);
printf("variance=%f\n",variance);
printf("standard deviation=%f\n",deviation);
}```

## Output

Enter the value of n

5

Enter the 5 real values

3

7

23

1

4

Sum = 38.0000

Mean ( Average ) = 7.6000

Variance = 63.039997

Standard deviation = 7.9397

## C PROGRAMMING –Viva Questions

1] Define pointer?

2] Define an array of pointer

3] Difference between ( x + i ) and * ( x + i )

4] Define array