Answer:
Probability that the calculator works properly for 74 months or more is 0.04 or 4%.
Step-by-step explanation:
We are given that the life span of a calculator has a normal distribution with a mean of 60 months and a standard deviation of 8 months.
Firstly, Let X = life span of a calculator
The z score probability distribution for is given by;
Z = 
~ N(0,1)
where, 
= population mean = 60 months
= standard deviation = 8 months
Probability that the calculator works properly for 74 months or more is given by = P(X 
74 months)
P(X 74) = P( 
) = P(Z 1.75) = 1 - P(Z < 1.75)
= 1 - 0.95994 = 0.04
Therefore, probability that the calculator works properly for 74 months or more is 0.04 or 4%.
x represents the number of lawns weeded by Gwen and y represents the number of dogs walked by Fabio.
Gwen charges $12 each time she weeds a yard and Fabio charges $9 each time he walks a dog.
So, for x number of weeds, Gwen earned 12x and for y number of dogs walked, Fabio earned 9y.
They need at least $510 to purchase the new gaming station.
Therefore,
12x + 9y ≥ 510
Also, the number of dog walks that Fabio has scheduled should not be more than twice the number of yards Gwen has scheduled to weed.
Therefore,
y ≤ 2x
Also, Fabio will walk at least 25 dogs.
Therefore,
y ≥ 25
Hence, the constraints are:
12x + 9y ≥ 510
y ≤ 2x
y ≥ 25
Answer:
3y+4
Step-by-step explanation:
9y-6y=3y
Answer:
73/80
Step-by-step explanation:
multiples of 11 between 1 and 80 are 11,22,33,44,55,66,77
number of terms=7
P(multiple of 11)=7/80
P(not a multiple of 11)=1-7/80=73/80
