Answer:
we can conclude that there is no significant evidence to conclude that the mean score in 2010 differs from the mean score in 2009.
Step-by-step explanation:
H0 : μ = 582
H1 : μ < 582
Test statistic :
T = (xbar - μ) ÷ σ/√n
Xbar = 515 ; n = 20 ; σ = 120
T = (515 - 582) ÷ 120/√20
T = -67 / 26.832815
T = 2.50
Pvalue at t score = 2.50 ; df = 19 is 0.0187
At α = 0.0187
Pvalue > α ; Hence, we fail to reject the Null
Hence, we can conclude that there is no significant evidence to conclude that the mean score in 2010 differs from the mean score in 2009.
I believe the answer would be a.
Answer:
B. 455
Step-by-step explanation:
The order in which the toppings are chosen is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
3 toppings from a set of 15. So
455 3-topping sundaes can be made.
Answer:
cost of a taco: $1.25
cost of a burrito: $2.50
Step-by-step explanation:
Let the cost of a taco be $t and the cost of a burrito be $b.
t +3b= 8.75 -----(1)
4t +2b= 10
Divide both sides by 2:
2t +b= 5
Making b the subject of formula:
b= 5 -2t -----(2)
Substitute (2) into (1):
t +3(5 -2t)= 8.75
Expand:
t +3(5) +3(-2t)= 8.75
t +15 -6t= 8.75
t -6t= 8.75 -15
-5t= -6.25
t= -6.25 ÷(-5)
t= 1.25
Substitute t= 1.25 into (2):
b= 5 -2(1.25)
b= 5 -2.5
b= 2.50
Thus, the cost of a taco is $1.25 and the cost of a burrito is $2.50.
