Answer: 32 copies of hardcover version.
Step-by-step explanation: Suppose the quantity of hardcover version copies sold is H and the paperback copies is P.
1) A store sells a total of 70 copies:
H + P = 70
2) One hardcover is sold for $15 and one paperback for $11.50. In one month was charged $917:
15H + 11.5P = 917
Solving the system of equations:
H + P = 70 (I)
15H + 11.5P = 917 (II)
Since it is asked for the hardcover version, find H.
Multiply equation (I) by -11.5:
-11.5H - 11.5P = - 805 (III)
Add (II) and (III):
-11.5H - 11.5P = - 805
15H + 11.5P = 917
3.5H = 112
H = 32
In one month, it was sold 32 hardcover version of a book.
Answer:
Mean absolute deviation (MAD) of a data set is the average distance between each data value and the mean.
Step-by-step explanation:
Answer:
Step-by-step explanation:
Is it 25
Answer:
The answer is below
Step-by-step explanation:
Given that:
Mean (μ) = 1.93, standard deviation (σ) = 1.08 pounds, sample (n) = 62.
the mean weight of discarded plastic for all household is given by:
The standard deviation of discarded plastic for all household is given by:
The confidence (c) = 90% = 0.9
α = 1 - c = 1 - 0.9 = 0.1
α/2= 0.1/2 = 0.05
The z score of 0.05 corresponds to the z score of 0.45 (0.5 - 0.05) which is 1.645. i.e.
The margin of error (E) =
The confidence interval =
We are 90% confidence that the value is between 1,7044 and 2.1556