In the past the average age of employees of a large corporation has been 40 years. recently, the company has been hiring older individuals. in order to determine whether there has been an increase in the average age of all the employees, a sample of 25 employees was selected. the average age in the sample was 45 years with a standard deviation of 5 years. assume the distribution of the population is normal let α= 0.5 a, state the null and the alterative hypothesis b, test to determine whether or not the mean age of all the employees is significantly more than 40 years.
answer: the answer should be 80%
the correct answer is that a rose bush costs $10 and a shrub costs $4
to solve this, start by writing equations for what each spent. use x for the cost of a rose bush and y for the cost of a shrub. below would be the equations for each.
rob: 8x + 5y = 100
amy: 8x + 8y = 112
now to find the cost, we multiply rob's equation by -1 and add them together. this will get x to cancel and allow us to solve for y.
-8x - 5y = -100
8x + 8y = 112
3y = 12
y = 4
so we know the cost of a shrub is $4. now we can plug that in to either of the original equations and solve for the rose bush cost.
8x + 5y = 100
8x + 5(4) = 100
8x + 20 = 100
8x = 80
x = 10
which means that a rose bush costs $10.