A Internet provider has implemented a new process for handling customer complaints. Based on a review of customer complaint data
1 answer:
Answer:
<em>a)</em><em> The mean time for handling a customer complaint under the new process using 95% confidence level is between 25.0 min. and 27.5 min. </em>
<em>b) </em><em>there is no substantial evidence</em><em> </em><em>(in 95% confidence level) that the new process has reduced the mean time to handle a customer complaint.</em>
<em>c) </em><em>The population about which inferences from these data can be made is the people following the new implemented plan when handling customer complaints.</em>
Step-by-step explanation:
the random sample of the response times of 50 customers who had complaints has
size=50
mean≈26.218
standard deviation ≈4.42
a. Confidence interval can be estimated using the formula:
M± where
- M is the sample mean (26.22)
- z is the corresponding z-score for the 95% confidence interval (1.96)
- s is the sample standard deviation (4.42)
- N is the sample size (50)
When we put the numbers in the formula, mean time for handling a customer complain under the new process using 95% confidence interval is:
26.22±≈ 26.22±1.225 i.e. between 25 and 27.45
b<em>. </em>According to the customer complaint data for the past 2 years, the mean time for handling a customer complaint was 27 minutes. After the plan, estimated mean time for handling customer complaint is between <em>25.0 min. and 27.5 min. with 95% confidence. </em>Since 27 min. is within this interval, we can conclude that there is no substantial evidence (in 95% confidence level) that the new process has reduced the mean time to handle a customer complaint.
c. The population about which inferences from these data can be made is the people following the new implemented plan when handling customer complaints.
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Answer:
No lower than $208, and no higher than $956.8
Step-by-step explanation:
Notice that the revenue (income) function is represented by a quadratic expression (a parabola with branches pointing down), and the cost function is linear with negative slope.
When we plot them, we obtain the graphs shown in the attached image. Notice as well that there are two points of intersection for these two functions. The revenue exceeds (lays above) the cost in between the two points of intersection (marked in red and green).
For the company to make a profit, the revenue has to be larger than the cost, so we study the limiting values for that to happen, which is the points of intersection of these two curves.
The first one (pictured in red) is associated with coordinates (35, 33488) which tells us that is the production of 35 chairs with a revenue of $33,488. That is a cost per chair of $33,488 / 35 = $956.8
The second intersection (pictured in green) is associated with coordinates (125, 26000), which tells us that is the production of 125 chairs with a revenue of $26,000. That is a cost per chair of $26000 / 125 = $ 208
So these values give us the minimum and maximum that the company can charge to make a profit.
Answer:
C
Step-by-step explanation:
Use formula
where
I = interest
P = rpincipal
r = rate (as decimal)
t = time (in years)
In your case,
P = $800
r = 0.04 (4%)
t = 5,
so