Answer:
$3.10
Step-by-step explanation:
Answer: The probability in (b) has higher probability than the probability in (a).
Explanation:
Since we're computing for the probability of the sample mean, we consider the z-score and the standard deviation of the sampling distribution. Recall that the standard deviation of the sampling distribution approximately the quotient of the population standard deviation and the square root of the sample size.
So, if the sample size higher, the standard deviation of the sampling distribution is lower. Since the sample size in (b) is higher, the standard deviation of the sampling distribution in (b) is lower.
Moreover, since the mean of the sampling distribution is the same as the population mean, the lower the standard deviation, the wider the range of z-scores. Because the standard deviation in (b) is lower, it has a wider range of z-scores.
Note that in a normal distribution, if the probability has wider range of z-scores, it has a higher probability. Therefore, the probability in (b) has higher probability than the probability in (a) because it has wider range of z-scores than the probability in (a).
Answer:
Manufacturers has to produce 63 DVD/Blu-Ray players to achieve a minimum cost of $644
Step-by-step explanation:
The cost equation is given as:

This is a quadratic equation in general form, which is:

Matching, we can say:
a = 0.04
b = -5
c = 800
The minimum occurs at 
and the minimum value would be to place that "x" value into the equation.
First, we find the minimum using values of a and b:

Plugging this into original, we get:

Rounding off to nearest whole number, we can say:
Manufacturers has to produce 63 DVD/Blu-Ray players to achieve a minimum cost of $644