Carry out the mult.: f(x) = -[x^2 - 21x + 9x - 189]
Combine like terms: f(x) = -[x^2 - 12x - 189]
Eliminate the brackets [ ]: f(x) = -x^2 + 12x + 189
Identify coefficients a, b and c: a= -1, b=12, c=189
The equation of the axis of symmetry is x = -b/(2a), which here equals
x = -(12)/[2(-1)], or x = 6
This is also the x-coordinate of the vertex. Plug x=6 into the original equation to calculate the y-coordinate.
Answer:
p = 0.07
p-hat = 0.035
p0 = 0.07
p-value = 0.003
Step-by-step explanation:
p = population parameter, in this case, the rate of infestations across all trees in the forest
p-hat = test statistic, in this case, the rate of infestations found in the sample of trees, i.e. those in Doug's backyard
p0 = the null hypothesis, in this case, the rate of infestations within the forest is correctly evaluated at 0.07 or 7%
p-value = the likelihood any difference between p and p-hat is down to chance
In this case 0.003 as the p-value means there is only 0.3% probability of our statistic value of 0.035 being down to variability and chance meaning it is 99.7% likely that there is some reason behind this difference;
We would accept the alternative hypothesis which says the current parameter value, 0.07, is in fact incorrect (either too high or too low, in this case, likely too high).
Answer:
180 hamburgers
120 hotdogs
Step-by-step explanation:
In this question, we are asked to calculate the number of hamburgers and hotdogs sold by a company given the amount made by them and the total number of these snacks sold
We proceed as follows;
Let the amount of hotdogs sold be x and the amount of hamburgers sold be y.
We have a total of 300 snacks sold, mathematically;
x + y = 300 ..........(I)
Now let’s look at the prices.
x number of hotdogs sold at $2, this give a total of $2x hotdogs
y number of hamburgers sold at $3, this give a total of $3y.
Adding both to give total, we have ;
2x + 3y = 780.......(ii)
This means we have two equations to solve simultaneously. From equation 1, we can say x = 300 -y
Now let’s insert this in the second equation;
2(300-y) + 3y = 780
600-2y + 3y = 780
y = 780-600 = 180
Recall; x + y = 300
x = 300 -y
x = 300-180 = 120
