5x+2y = 20
For every hardcover book (x) you will be charged 5$.
For every paperback book (y) you will be charged 2$.
The amount of both types of books you buy has to be under or equal to 20$
Answer:
Step-by-step explanation:
x/10=7
x=70
Answer:
68% of jazz CDs play between 45 and 59 minutes.
Step-by-step explanation:
<u>The correct question is:</u> The playing time X of jazz CDs has the normal distribution with mean 52 and standard deviation 7; N(52, 7).
According to the 68-95-99.7 rule, what percentage of jazz CDs play between 45 and 59 minutes?
Let X = <u>playing time of jazz CDs</u>
SO, X ~ Normal(
)
The z-score probability distribution for the normal distribution is given by;
Z =
~ N(0,1)
Now, according to the 68-95-99.7 rule, it is stated that;
- 68% of the data values lie within one standard deviation points from the mean.
- 95% of the data values lie within two standard deviation points from the mean.
- 99.7% of the data values lie within three standard deviation points from the mean.
Here, we have to find the percentage of jazz CDs play between 45 and 59 minutes;
For 45 minutes, z-score is =
= -1
For 59 minutes, z-score is =
= 1
This means that our data values lie within 1 standard deviation points, so it is stated that 68% of jazz CDs play between 45 and 59 minutes.
Answer:
21x+53
Step-by-step explanation:
<span>cost of two pair of jeans- $55
cost of belt-$ 5.85
tax- $5.85
total bill- $67.8
as sue paid $70 to the cashier for the bill amount so she will get $2.2 change in return.</span>