Answer:
x=11 (read below)
Step-by-step explanation:
7 + x = 18
<em>Subtract 7 from both sides</em>
x=11
It's quite simple because if you do something to one side of the equation, you need to do it to the other because otherwise the equation won't be equal. This is how you need to simplify most problems, by taking something from one side and taking from the other as well.
Answer:
1. A matched-pairs t-test is valid, despite the sample being a small representation of the population, because the sample is a simple random sample and has a distribution with a single peak.
Step-by-step explanation:
The matched-pairs test is valid, for the reasons given in choice 1. Here's why:
- We do have matched pairs, not a 2-sample t-test, because each two are paired by the house they live in. Husband and wife live together: it's safe to pair them. (This rules out option 5.)
- Check conditions: The sample is large enough (fulfilling the <u>sample size condition)</u>. The sample data is fairly normal, although we don't know the population data, and the sample size is over 40, so we consider it a fairly large sample (fulfilling the <u>nearly normal condition)</u>. We don't know about outliers, but we'll have to assume Ted doesn't have any, because they aren't mentioned.
Parallelogram as well as a quadrilateral with pairs of equal and parallel opposite sides
Answer:
The residual age of a lion whose nose is 11% black and is 1.9 years old is -0.15.
Step-by-step explanation:
In regression, the difference between the observed value of the dependent variable (<em>y</em>) and the predicted value (
) is known as the residual (<em>e</em>).
The least square regression line is used to predict the value of the response or dependent variable (<em>y</em>) from the known value of the explanatory or independent variable (<em>x</em>).
The general form of a least square regression line is:
The equation of the least squares regression line to predict the relationship between age (in years) and proportion of blackness in the lion’s nose is:
Compute the predicted value of <em>y</em> for <em>x</em> = 0.11 as follows:
The predicted value of <em>y</em> is, 
.
The observed value of the age of lion whose nose is 11% black is, <em>y</em> = 1.90.
Compute the residual age of this lion as follows:
Thus, the residual age of a lion whose nose is 11% black and is 1.9 years old is -0.15.
Answer:
- $70
- y = 25 + 0.9x
- $250
Step-by-step explanation:
1. 10% of $50 is $5, so the purchases would come to $50 -5 = $45. Added to the $25 membership fee, the total cost for the year would be
$45 +25 = $70
2. The member pays $25 even if no purchases are made. Then any purchases are 100% - 10% = 90% of the marked price. So, the total is ...
y = 25 + 0.90x
3. $25 is 10% of $250, so that is the amount the member would have to purchase to break even on cost.
If you like, you can compare the cost without the membership (x) to the cost with the membership (25+.9x) and see where those costs are equal.
x = 25 +0.9x . . . . . x is the spending level at which there is no advantage
0.1x = 25 . . . . . . . . subtract 0.9x
25/0.1 = x = 250 . . . divide by 0.1
