MATH 533 Week 8 Final Exam 1. Questions With Answers. Latest.Question 1. 1. (TCO A) An assembly line worker samples 20 items off the line every hour
and
... [Show More] measures the width of each item (in units of inches). The results for one such hour are
given here.
13.8 15.8 14.2 14.8 15.2
15.1 14.5 15.1 15.5 14.6
14.8 14.8 15.3 15.2 14.9
14.9 14.7 15.6 15.1 14.7
a. Compute the mean, median, mode, and standard deviation, Q1, Q3, Min, and Max for
the above sample data on width of items.
b. In the context of this situation, interpret the Median, Q1, and Q3. (Points : 33)
Variable N N* Mean SE Mean StDev Variance Squares Minimum Q1
C1 20 0 14.930 0.105 0.468 0.219 4462.260 13.800 14.700
Variable Median Q3 Maximum Range Skewness
C1 14.900 15.200 15.800 2.000 -0.42
mean = 14.930
median = 14.900
mode = 15.1
standard deviation = 0.468
Q1 =14.700
Q3 = 15.200
02:18:02
Min = 13.800
Max .= 15.800
b. In the context of this situation, interpret the Median, Q1, and Q3.
The Lower quartile, Q1 is the 25th percentile :
Q1 : 14.700
distance 1: Median - Q3 =
14.900 - 15.2 = 0.3
distance 2: Median - Q1 =
14.900 - 14.7= 0.2
The upper quartile, is the 75th percentile: Q3 : 15.200
Q3-Q1 is the interquantile range.
the distance D1 between and median
and Q3 is greater than that between the median and Q1, then we say distribution is be
skewed to the right.
D1 < D2 then we say
The lower quartile, Q1= 14.7 is the 25th percentile. The upper quartile, Q3=15.2 is the 75th
percentile.
Q3-Q1 is the interquantile range. If the distance between and median and Q3 is greater than
that between the median and Q1, the distribution may be skewed to the right.
25% of the values are less than or equal to Q1 : 14.7
50% of the values are less than or equal to Q2: 14.900
75% of the values are less than or equal to Q3: 15.2
Variable
N N* Mean SE Mean StDev Variance Squares Minimum Q1
C1 20 0 14.930 0.105 0.468 0.219 4462.260 13.800
14.700
Variable Median Q3 Maximum Range Skew ness
C1 14.900 15.200 15.800 2.000 -0.42
mean = 14.930
median = 14.900
mode = 15.1
standard deviation = 0.468
Q1 =14.700
Q3 = 15.200
Min = 13.800
Max .= 15.800
Question 2. 2. (TCO B) JR Trucking buys tires from three suppliers: Goodyear, Michelin,
and Bridgestone. Data on the last 1,000 tires that were purchased are described in the table
below.
Defective Not
Defective
Total
Goodyear 5 495 500
Michelin 6 294 300
Bridgestone 10 190 200
Total 21 979 1000
If you choose a tire at random, then find the probability that the tire
a. was made by Michelin.
b. was made by Goodyear and was defective.
c. was not defective, given that the tire was made by Bridgestone. (Points : 18)
Question 3. 3. (TCO B) Historically, 70% of your customers at Rodale Emporium pay for
their purchases using credit cards. In a sample of 20 customers, find the probability that
a-P(A) = 300/1000=.3
b-P (a)= 500/1000= .005
c-P(A)= 190/979= .194
a. exactly 14 customers will pay for their purchases using credit cards.
b. at least 10 customers will pay for their purchases using credit cards.
c. at most 12 customers will pay for their purchases using credit cards. (Points : 18)
Question 4. 4. (TCO B) Fuel efficiency for cars made in the United States is normally
distributed with a mean of 28.8 mpg and a standard deviation of 8.2 mpg.
a. What percentage of cars made in the United States have fuel efficiency above 40 mpg?
b. What percentage of cars made in the United States have fuel efficiency between 25 and 35
mpg?
c. A special tax credit is planned for the best (highest) 8% of cars made in the United States
in terms of fuel efficiency. How high must the fuel efficiency be in order to qualify for this
special tax credit? (Points : 18)
a- P(x=14) n= 20 p =0.7 : = 0.191639
B- P(X>=10) = 1- P(9) = 1- .0171448 = 0.9828552
c- P(X<=12) = 0.227728
Question 5. 5. (TCO C) A large-sized bag of Neato Chips should contain 16 oz of potato
chips. A sample of 50 large-sized bags is selected with the following results.
Sample Size = 50
Sample Mean = 15.85 oz
Sample Standard Deviation = 1.53 oz
a. Construct a 95% confidence interval for the mean amount of contents per bag. .
b. Interpret this interval.
c. How large a sample size will need to be selected if we wish to have a 99% confidence
interval with a margin for error of .10 oz? (Points : 18) [Show Less]