Stat-312: Quiz #04
Name:
Key
1. At a bank ATM, customers arrive randomly with a mean inter-arrival time of 5 minutes.
(a) What is the chance that the next customer will arrive in exactly 5 minutes?
This is a CONTINUOUS random variable
P(X = 5 minutes) =
(
Stat-312: ICE #05 Sampling Distributions
Name:
With Answers
1. Suppose that the weights of adult steers at US farms are normally distributed with a population mean of
500 pounds and a population standard deviation of 100 pounds. Based on these parameters,
STAT 312
Lucia Mercado
Homework 7
Section 9.4
9.13)
a. H0: 1=2, HA: 1 not equal 2
t = 1.0601 p > 0.05 so FAIL TO REJECT. No difference between diffusors.
b. sample is simple random sample from population, samples independent of one
another, equal popu
STAT 312
Lucia Mercado
Homework Assignment #8
Section 9.6
26)
a. @0.01 significance, is average strength less at 2 days than at 7 days?
Null Hypothesis: =0
Alt. Hypothesis: <0
On excel, paired t-test. t=-9.37, p=0.00, <0.05
Reject null hypothesis, so
Stat-312: ICE #04 Continuous Probability Distributions
Name:
With Answers
1. A random number generator is used to produce values between 10 and 20, e.g., X = 10*rand() + 10.
(a) Sketch the Probability Density Function (PDF) and Cumulative Distribution Fun
Stat-312: Quiz #01
Name:
Key
1. (a) Data in the table represent length measurements of a rod, in cm. Calculate the following statistics for the
data (verify data entry using the sample st. dev.!):
9.22
9.47
9.96
10.52
10.80
9.53
n=
xn =
10.69
9.50
9.96
30
Stat-312: Quiz #03
Name:
Key
1. A vending machine accepts nickels, dimes, and quarters, and rejects any objects that it does not recognize
as one of these coins. Unfortunately, the machine also randomly rejects valid coins. The probability
distribution fo
Frequency
Stat-312: Quiz #02
Name:
Key
1. The histogram below is based on observations of 35 flash drives. The number of defective sectors on each
drive was counted by an inspection program. The histogram was generated in Minitab using cutpoint
binning, u
Stat-312: ICE #03 Discrete Probability Distributions
Name:
With Answers
1. The objective of this problem is to determine an empirical discrete probability distribution for a coin flip
experiment.
(a) Flip the coin 25 times, and record the tally of Heads a
Stat-312: ICE #01 Summary Measures and Sampling
Name:
With Answers
1. A camera manufacturer wants to monitor the quality of silicon windows received from four different
suppliers. As they are received, each window is visually inspected; the inspector rate
Prob. Dens.
(F-1)
Stat-312: Quiz #05
Name:
Key
1. The body temperature of healthy adults in the US has an unknown distribution. Nationwide data collected
by hospitals over the past decade have a mean value of 98.2F and a standard deviation of 1.6F. These
Stat-312: ICE #02 Frequency Histograms, Control Charts & SPC
Name:
With Answers
1. The histogram below is based on measurements of the number of scratches on a camera lens determined by
visual inspection. Recall that Minitab cutpoint binning puts data val
STAT 312
Lucia Mercado
Homework 7
Section 9.4
9.13)
a. H0: 1=2, HA: 1 not equal 2
t = 1.0601 p > 0.05 so FAIL TO REJECT. No difference between diffusors.
b. sample is simple random sample from population, samples independent of one
another, equal populati
Sean Basalyga What Makes A Good Design
The consumer is a very hard person to please. It must be easy to use, affordable, somewhat attractive and most important, something the consumer will want. What I think all this is based on is design. A good de
Garcia 1
Victor Garcia STAT 312-074 HW 08: Due Monday, 15 Nov 2010 9.7: P. 446 # 9.35, 9.36 10.4: PP. 484-486 # 10.2, 10.3, 10.4, 10.5 9.7 #9.35: Ho: a=b=c=d; Ha: not all s are equal Drug Regimen Obs. Result Severe Not Severe Totals A 714 9630 10344 B 785
Exponential Distribution
A special type of a continuous random variable is known as the exponential
distribution.
= for x 0
The function depends on the parameter
in order to find probabilities associated
with the random variable.
*This distribution is u
Going Beyond our Lovely Empirical Rule
The Empirical Rule works nicely when you are
dealing with a whole number of standard
deviation away from the mean i.e. 1, -2, or 3
What if you want to find the percentage of
students that are 1.5 or -2.6 standard dev
Normal Distribution
There is a special type of theoretical bell shaped distribution called the
normal distribution, also known as the Gaussian Distribution
Properties of normal distribution
1. Area under the curve equals 1 or 100%
2. Symmetric over the me
Statistics. What is it?
Statistics
Statistics: the science/art of collecting, analyzing, and interpreting data.
Data: values or categories obtained from observational units
Observational unit: a person, place or thing being studied
So where the heck do we
Stat-312: ICE #01 Summary Measures and Sampling
Name:
With Answers
1. A camera manufacturer wants to monitor the quality of silicon windows received from four different
suppliers. As they are received, each window is visually inspected; the inspector rate
Sample Mean
Stat-312: Quiz #02
Name:
Key
1. Interpret the control chart below, according to the rules listed on the back of this page.
Process is:
5.4
UCL=5.3692
IN CONTROL / OUT OF CONTROL
5.3
5
6
5.2
Explanation: if the process is out of
5.1
_
_
control
Stat-312: ICE #06
Name:
1. A rod has spec limits for length of 5.0 cm 0.1. The data values listed below represent length
measurements for a sample from the production line, listed in centimeters:
5.062
5.012
5.035
5.012
5.088
4.982
5.048
5.084
4.964
5.034