Answer:
x = 6, y = 3
Step-by-step explanation:
Let Sally's age be x and Tomas's age be y.
Sum of Sally's age plus twice Tomas's age: x + 2y = 12
Difference of Sally's age and Tomas's age: x - y = 3
Multiply the second equation by two and add it to the first equation to get
3x = 18, which means x = 6.
Plug 6 in for x in the second equation to get 6 - y = 3, which means y = 3.
I think the answer is 6 from the information you provided.
B is your answer! All you do for this equation is go oh look m=2/7 well this means y=2/7x and you have a -12 so than you just plug it in. To get y=2/7x-12
Answer:
(B) 0.74 + or - 2.797 × 0.22/√25
Step-by-step explanation:
Confidence Interval = mean + or - t × sd/√n
mean = 0.74 hours
sd = 0.22 hours
n = 25
degree of freedom = n - 1 = 25 - 1 = 24
Confidence level = 99%
t-value corresponding to 24 degrees of freedom and 99% confidence level is 2.797
Confidence Interval = 0.74 + or - 2.797 × 0.22/√25
