Part 6: Quantitative Methods and Tools Flashcards
A project is being conducted in a hospital clinic. Which of the following is not considered discrete data?
A) Patient weight
B) Result of a pass/fail medical test
C) Error in a medical record
D) Number of patient visits
A) Patient Weight
A projected is being conducted in a manufacturing facility. Which of the following is not considered continuous data?
A) The length of a component
B) Fill volume of a container
C) Number of nonconforming components
D) Time required for testing
C) Number of nonconforming components
The color of a car is on which measurement scale?
A) Nominal
B) Ordinal
C) Interval
D) Ratio
A) Nominal
A person’s height in feet is on which measurement scale?
A) Nominal
B) Ordinal
C) Interval
D) Ratio
D) Ratio
The rating of a service from poor to excellent is on which measurement scale?
A) Nominal
B) Ordinal
C) Interval
D) Ratio
B) Ordinal
A research team is doing a study of students at a college and would like to ensure that their sample has all four levels of students: freshmen, sophomores, juniors, and seniors. What sampling method is most appropriate for this study?
A) Double sampling
B) Stratified sampling
C) Simple random sampling
D) Multiple sampling
B) Stratified sampling
The waiting times in minutes for eight customers at a bank are: 5, 8, 12, 3, 2, 7, 6, 5. What are the mean and median for this sample of waiting times?
A) Xbar = 5.5 min, M = 6 min
B) Xbar = 6 min, M = 5 min
C) Xbar = 6 min, M = 5.5 min
D) Xbar = 6 min, M = 6 min
C) Xbar= 6 min, M = 5.5 min
The lengths in inches for a sample of seven components are: 3.2, 3.1, 3.4, 3.1, 3.2, 3.3, 3.2. What is the standard deviation for this sample?
A) s = 0.1069 in
B) s = 0.0114 in
C) s = 0.0098 in
D) s = 0.0989 in
A) s = 0.1069 in
The median of a population is much larger than the population mean. What can you say about the shape of the population distribution?
A) The distribution is symmetric
B) The distribution is right skewed
C) The distribution is left skewed
D) None of the above
C) The distribution is left skewed
A population has an exponential distribution. One hundred samples of size 40 are randomly collected and the 100 sample means are calculated. What is the approximate distribution of these sample averages?
A) Binomial
B) Normal
C) Uniform
D) Poisson
B) Normal
What is the formula for the population variance?
A) sum of (sample - population mean) / Population
B) sum of (sample - sample mean)^2 / (Sample population - 1)
C) sum of (sample - population mean)^2 / Population
D) sum of (sample - population mean)^2 / (Population - 1)
C) sum of (sample - population mean)^2 / Population
Σ (x-μ)^2 / N
A team would like to compare waiting times of customer by day of the week. Which of the following would be the most appropriate tool to use?
A) Histograms
B) Box plots
C) Scatter plots
D) Probability plots
B) Box plots
Which of the following descriptive statistics is not typically found in a box plot?
A) Minimum
B) Maximum
C) Mean
D) Median
C) Mean
Which of the following is an advantage of a stem and leaf plot compared to a histogram?
A) Stem and leaf plots contain more information than a histogram
B) Stem and leaf plots provide a depiction of the shape of the data
C) Stem and leaf plots provide a time reference
D) None of the above
A) Stem and leaf plots contain more information than a histogram
A team measured the time to failure of 20 components. They plotted the data in a normal probability plot (Page 95). What conclusions can be drawn?
A) The normal distribution is not a reasonable model for the time to failure
B) The Weibull distribution is a reasonable model for the time to failure
C) The normal distribution is a reasonable model for the time to failure
D) Not enough information provided to draw conclusions.
A) The normal distribution is not a reasonable model for the time to failure
The temperature of coffee is an important characteristic in a restaurant. The temperature of 15 randomly selected cups of coffee is measured and the average temperature is found to be 168°F. Which term best describes this average temperature?
A) Population
B) Sample
C) Parameter
D) Statistic
D) Statistic
A characteristic of a population is called a:
A) Sample
B) Statistic
C) Parameter
D) Probability
C) Parameter
The contingency table below describes the relationship between the number of nonconforming components produced and time of day.
Time Conforming Qty Nonconforming Qty
Day 94 5
Evening 87 10
Overnight 65 23
Totals 246 38
Given that a part is made overnight, what is the probability it is nonconforming?
A) 0.08
B) 0.61
C) 0.43
D) 0.26
D) 0.26
The probability of a part being defective is 0.02. What is the probability it is not defective?
A) 0.88
B) 0.98
C) 1.08
D) 2%
B) 0.98
The probability that event A occurs is 0.72. The probability that event B occurs is 0.03. What is the probability that events A and B both occur?
A) 0.0216
B) 0.75
C) 0.69
D) Not enough information provided
D) Not enough information
If the probability that event A occurs is 0.40, the probability that event B occurs is 0.13, and A and B are mutually exclusive events, what is the probability that events A and B both occur?
A) 0
B) 0.052
C) 0.53
D) 1.27
A) 0
The time between arrivals at a store has an exponential distribution with mean five minutes. What is the probability that the time between arrivals is less than three minutes?
A) 0.9999
B) 0
C) 0.5488
D) 0.4512
D) 0.4512
X has a normal distribution with mean 15 and standard deviation 2. What is the probability that X is greater than 18?
A) 0.0668
B) 0.8554
C) 0.9332
D) 0.1446
A) 0.0668
Which of the following probability distributions is not symmetric?
A) Normal
B) t
C) Uniform
D) None of the above
D) None of the above