The population mean on a statistics exam is 72, with a standard deviation of 12. the population average on the class project is 95, with a standard deviation of 4. if the exam is 70% of the final grade and the project 30%, what are the mean and standard deviation of final grades?

mean = 54

standard deviation = 6.24

Explanation:

given data

mean a = 72

standard deviation σx = 12

average b = 95

standard deviation σy = 4

final grade Z = 70%  = 0.70

project y = 30%  = 0.30

to find out

mean and standard deviation

solution

final grade equation will be here

final grade = 0.70x + 0.30 y   a

here x is statics grade and y is class project

so

mean will be 0.70x + 0.30 y

mean = 0.70 (a) + 0.30 (b)

mean = 0.70 (12) + 0.30 (95)

mean = 54

and

standard deviation = 0.70x + 0.30 y

standard deviation = 0.70(σx) + 0.30 (σy)

standard deviation = 0.70(12) + 0.30 (4)

standard deviation = 6.24

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles