Answer:
The difference is <em>2 inches</em>
Step-by-step explanation:
Firstly, we identify the equation as given in the question;
y = 1.42105x - 32.2632
We need to know which of the two is the dependent variable i.e y-value and which is the independent variable x-value between the brothers' heights and the sisters' heights. To do this, we have to start with an assumption and check which of the two is for the brothers' or for the sisters,
Let's say the brothers' heights is x, we select any of the data points; (68,64)
we input this into the line of best fit equation; 64 =1.42105(68) - 32.2632 = 96.6314-32.2632= 64.3682
We can see the value on the left hand side of the equation correlates with that on the right hand side. This confirms our assumption that the brothers' heights refer to the independent variable x.
Now, let's plug the values for the 71 inches heights
y = 1.42105(71) - 32.2632 = 68.63 approximately 64
In the table, we can see that the predict sister height at that particular data point is 71 inches. The difference between the predicted height and the actual height is thus 71-69 = 2 inches
The following table shows the total number of quizzes taken in high school. how many quizzes are taken per week?
Answer:
0 ≤ t ≤ 5.
Step-by-step explanation:
In the function 
, 
is the independent variable. The domain of 
is the set of all values of that this function can accept.
In this case, is defined in a real-life context. Hence, consider the real-life constraints on the two variables. Both time and volume should be non-negative. In other words,
.
.
The first condition is an inequality about , which is indeed the independent variable.
However, the second condition is about , the dependent variable of this function. It has to be rewritten as a condition about .
![\begin{aligned} f(t) &\ge 0 &&\text{Assumption} \cr 80000 - 16000\, t& \ge 0 && \text{Definition of} ~ f \cr 80000 & \ge 16000\, t && \begin{aligned}&\text{Add $16000\, t$} \\[-0.5em] & \text{to both sides of the inequality}\end{aligned} \cr 5 &\ge t &&\begin{aligned}&\text{Divide both sides of} \\[-0.5em] & \text{the inequality by $16000$}\end{aligned} \cr t &\le 5 && \text{Flip the inequality}\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%20f%28t%29%20%26%5Cge%200%20%26%26%5Ctext%7BAssumption%7D%20%5Ccr%2080000%20-%2016000%5C%2C%20t%26%20%5Cge%200%20%26%26%20%5Ctext%7BDefinition%20of%7D%20~%20f%20%5Ccr%2080000%20%26%20%5Cge%2016000%5C%2C%20t%20%26%26%20%5Cbegin%7Baligned%7D%26%5Ctext%7BAdd%20%2416000%5C%2C%20t%24%7D%20%5C%5C%5B-0.5em%5D%20%26%20%5Ctext%7Bto%20both%20sides%20of%20the%20inequality%7D%5Cend%7Baligned%7D%20%5Ccr%205%20%26%5Cge%20t%20%26%26%5Cbegin%7Baligned%7D%26%5Ctext%7BDivide%20both%20sides%20of%7D%20%5C%5C%5B-0.5em%5D%20%26%20%5Ctext%7Bthe%20inequality%20by%20%2416000%24%7D%5Cend%7Baligned%7D%20%5Ccr%20t%20%26%5Cle%205%20%26%26%20%5Ctext%7BFlip%20the%20inequality%7D%5Cend%7Baligned%7D)
.
Hence, t ≤ 5.
Combine the two inequalities to obtain the domain:
0 ≤ t ≤ 5.
