4. Construct and interpret a 95% confidence interval for the true mean response time of calls to the bank's customer service center. 5. Is the customer service center meeting its goal of answering calls in less than 30 seconds? Give appropriate evidence to support your answer.
Percentage
A percentage is a number indicated as a fraction of 100. It is a dimensionless number often expressed using the symbol %.
Algebraic Expressions
In mathematics, an algebraic expression consists of constant(s), variable(s), and mathematical operators. It is made up of terms.
Numbers
Numbers are some measures used for counting. They can be compared one with another to know its position in the number line and determine which one is greater or lesser than the other.
Subtraction
Before we begin to understand the subtraction of algebraic expressions, we need to list out a few things that form the basis of algebra.
Addition
Before we begin to understand the addition of algebraic expressions, we need to list out a few things that form the basis of algebra.
![(d) Interpret the interval from part (c) in context.
4. Construct and interpret a 95% confidence interval for the true mean response time of calls to
the bank's customer service center.
5. Is the customer service center meeting its goal of answering calls in less than 30 seconds?
Give appropriate evidence to support your answer.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F2db6e2a1-de3c-43ab-9ac3-a4e655f7b338%2F4475a3c3-1d4d-4926-80fc-3a81fbefec64%2Ffrh2ou_processed.jpeg&w=3840&q=75)
![case closed
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Refer to the chapter-opening Case Study on page 000. The bank manager wants to know whether
or not the bank's customer service agents generally met the goal of answering incoming calls in
less than 30 seconds. We can approach this question in two ways: by estimating the proportion p
of all calls that were answered within 30 seconds or by estimating the mean response time µ.
Some graphs and numerical summaries of the data are provided below.
35
25-
15-
Call response time (seconds)
00
7,5
15.0
22.5
30.0
37.5
45.0
Call response time (seconds)
Descriptive Statistics: Call response time (sec)
Variable
N
Мean
SE Mean
StDev
Minimum
Q1
18.353
11.761
1.000
9.000
Call response time
(sec)
241
0.758
1. Describe the distribution of call response times for the random sample of 241 calls.
2. About what proportion of the call response times in the sample were less than 30 seconds?
Explain how you got your answer.
3. The bank’s manager would like to estimate the true proportion p of calls to the bank’s
customer service center that are answered in less than 30 seconds.
(a) What conditions must be met to calculate a 95% confidence interval for p? Show that the
conditions are met in this case.
(b) Explain the meaning of 95% confidence in this setting.
(c) A 95% confidence interval for p is (0.783, 0.877). Give the margin of error and show how
it was calculated.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F2db6e2a1-de3c-43ab-9ac3-a4e655f7b338%2F4475a3c3-1d4d-4926-80fc-3a81fbefec64%2F13h9u3p_processed.jpeg&w=3840&q=75)
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