The given data set of 40 scores that consists of chemistry final marks is given below:

Calculation:

The formula to calculate the mean is,

X¯=∑1nXn=X1+X2+X3+...+Xnn (1)

Where,

• X is the number of final scores.
• n is the total number of final scores.

The sum of the 40 final scores is given below.

∑140X={93+94+95+91+97+75+78+76+90+77+85+99+99+89+83+94+92+94+79+86+99+86+97+77+80+81+89+96+80+83+77+76+84+87+98+85+94+94+92+81}=3,502

Substitute 3502 for ∑140X and 40 for n in equation (1),

Mean=3,50240=87.55

Thus, the mean is 87.55.

Median:

For calculation of median, arrange the data in ascending or descending order. Now data is arranged in descending order as shown below:

The formula to calculate the median for even data is shown below.

Median=(n2)th term+(n2+1)th term2

The total number of terms in the data is 40 so, substitute 40 for n in the above formula.

Median=(402)th term+(402+1)th term2=(20)th term+(21)st term2 (2)

20th term from the arranged data is 89 and the 21st term is 87.

Substitute 89 for 20th term and 87 for 21st term in equation (2).

20th term+21st term2=89+872=1762=88

Thus, the median is 88.

Mode:

For calculation of mode, check the number that occurs most frequent. Since, 94 occur for 5 times in the table, thus 94 is the mode.