ANSWER
80%
EXPLANATION
Donovan got 20 questions correct and 5 questions incorrect.
This means that the total number of questions he attempted in the test is the sum of correct and incorrect questions:
Total = 20 + 5
Total = 25
To find the percentage of correct answers, we have to divide the number of correct answers by the total number of questions attempted and multiply by 100 (per cent).
That is:

That is the percentage of correct answers.
Answer:
75%
88.89%
Step-by-step explanation:
Given :
Mean = 70
Standard deviation = 12
Since the data is said to be extremely skewed, we apply Chebyshev's theorem rather than the empirical rule :
The minimum proportion of observation between 46 and 94
Chebyshev's theorem :
1 - 1 / k²
k = number of standard deviations from the mean
k = (94 - 70) / 12 = 24 / 12 = 2
Hence, we have ;
1 - 1/2²
1 - 1/4
1 - 0.25 = 0.75
Hence, The minimum proportion of observation between 46 and 94 is 75%
Between 36 and 106 :
k = (106 - 70) / 12 ;
k = 36/12 = 3
Hence,
1 - 1/3² = 1 - 1/9 = 8/9 = 0.8888 = 88.89%
The minimum proportion of observation between 34 and 106 is 88.89%
Answer:
10.50
Step-by-step explanation:
5% of 10 is 0.5
0.5+10=10.50
Answer:
a) correct option is
Poisson distribution is 6.2 and standard deviation is 2.49
b) probability for only 2 or less than 2 surgeries in a given day is 0.0536
Step-by-step explanation:
Given data:
mean number is given as 6.2
correct option is
Poisson distribution is 6.2 and standard deviation is 2.49
we know that variance is given as
hence, standard deviation is given as 
thus standard deviation is 2.49
correct option is
Poisson distribution is 6.2 and standard deviation is 2.49
b) probability for only 2 or less than 2 surgeries in a given day is


= 0.002029 + 0.012582+ 0.039006
= 0.053617
= 0.0536