Answer: Cost of DVD is $2.95 and cost of games is $3.2.
Step-by-step explanation:
Let the cost of DVD be x
Let the cost of games be y
So, According to question,
![2x+3y=\$15.50\\\\and\\\\3x+1y=\$12.05](https://tex.z-dn.net/?f=2x%2B3y%3D%5C%2415.50%5C%5C%5C%5Cand%5C%5C%5C%5C3x%2B1y%3D%5C%2412.05)
Now, we will apply " Substitution Method " i.e.,
![2x=15.50-3y\\\\x=\frac{15.5-3y}{2}](https://tex.z-dn.net/?f=2x%3D15.50-3y%5C%5C%5C%5Cx%3D%5Cfrac%7B15.5-3y%7D%7B2%7D)
Put this value of x in second equation:
![3x+y=12.05\\\\3\times \frac{15.5-3y}{2}+y=12.05\\\\46.5-9y+2y=12.05\times 2\\\\46.5-7y=24.1\\\\46.5-24.1=7y\\\\22.4=7y\\\\\frac{22.4}{7}=y\\\\3.2=y](https://tex.z-dn.net/?f=3x%2By%3D12.05%5C%5C%5C%5C3%5Ctimes%20%5Cfrac%7B15.5-3y%7D%7B2%7D%2By%3D12.05%5C%5C%5C%5C46.5-9y%2B2y%3D12.05%5Ctimes%202%5C%5C%5C%5C46.5-7y%3D24.1%5C%5C%5C%5C46.5-24.1%3D7y%5C%5C%5C%5C22.4%3D7y%5C%5C%5C%5C%5Cfrac%7B22.4%7D%7B7%7D%3Dy%5C%5C%5C%5C3.2%3Dy)
Now, substitute the value of y in equation of x:
![x=\frac{15.5-3y}{2}\\\\x=\frac{15.5-3\times3.2}{2}\\\\x=\frac{15.5-9.6}{2}\\\\x=\frac{5.9}{2}\\\\x=2.95](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B15.5-3y%7D%7B2%7D%5C%5C%5C%5Cx%3D%5Cfrac%7B15.5-3%5Ctimes3.2%7D%7B2%7D%5C%5C%5C%5Cx%3D%5Cfrac%7B15.5-9.6%7D%7B2%7D%5C%5C%5C%5Cx%3D%5Cfrac%7B5.9%7D%7B2%7D%5C%5C%5C%5Cx%3D2.95)
Hence, Cost of DVD is $2.95 and cost of games is $3.2.
Answer:
its a right ray
Step-by-step explanation:
Inverse variation means y=k/x (direct variation is y=kx) so we can use the info given to find the constant k
y=k/x
6=k/900
k=6(900)
k=5400 so the equation is:
y=5400/x or more accurately for this problem
t(v)=5400/v then:
t(800)=5400/800
t(800)=6.75 hours
Answer:
All but last statement are correct.
Step-by-step explanation:
- <em>If we were to use a 90% confidence level, the confidence interval from the same data would produce an interval wider than the 95% confidence interval.</em>
True. Confidence interval gets wider as the confidence level decreases.
- <em>The sample proportion must lie in the 95% confidence interval. </em>
True. Confidence interval is constructed around sample mean.
- <em>There is a 95% chance that the 95% confidence interval actually contains the population proportion.</em>
True. Constructing 95%. confidence interval for a population proportion using a sample proportion from a random sample means the same as the above statement.
- <em>We don't know if the 95% confidence interval actually does or doesn't contain the population proportion</em>
True. There is 95% chance that confidence interval contains population proportion and 5% chance that it does not.
- <em>The population proportion must lie in the 95% confidence interval</em>
False. There is 95% chance that population proportion lies in the confidence interval.
Answer:
13 sports books and 10 unknown books is 23 books
Step-by-step explanation:
we already know scott read 23 books total, we also know that he read 10 mystery books.
subtracting 10 unknown books from 23 total books, we get 13 sports books as your answer