Chapter 4: Q93E (page 193)
Construct a probability plot that will allow you to assess the plausibility of the lognormal distribution as a model for the rainfall data.
Short Answer
Yes, the rainfall data is likely to have a lognormal distribution.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 4: Q93E (page 193)
Construct a probability plot that will allow you to assess the plausibility of the lognormal distribution as a model for the rainfall data.
Yes, the rainfall data is likely to have a lognormal distribution.
All the tools & learning materials you need for study success - in one app.
Get started for free
There are two machines available for cutting corks intended for use in wine bottles. The first produces corks with diameters that are normally distributed with mean \({\bf{3}}\) cm and standard deviation \(.{\bf{1}}\) cm. The second machine produces corks with diameters that have a normal distribution with mean \({\bf{3}}.{\bf{04}}\)cm and standard deviation \(.{\bf{02}}\)cm. Acceptable corks have diameters between \({\bf{2}}.{\bf{9}}\)cm and \({\bf{3}}.{\bf{1}}\)cm. Which machine is more likely to produce an acceptable cork?
Two machines that produce wine corks, the first one having a normal diameter distribution with mean value \({\rm{3\;cm}}\) and standard deviation\({\rm{.1\;cm}}\), and the second having a normal diameter distribution with mean value \({\rm{3}}{\rm{.04\;cm}}\) and standard deviation\({\rm{.02\;cm}}\). Acceptable corks have diameters between \({\rm{2}}{\rm{.9}}\) and\({\rm{3}}{\rm{.1\;cm}}\). If \({\rm{60\% }}\) of all corks used come from the first machine and a randomly selected cork is found to be acceptable, what is the probability that it was produced by the first machine?
If \({\rm{X}}\) has an exponential distribution with parameter \({\rm{\lambda }}\), derive a general expression for the \({\rm{(100p)}}\)th percentile of the distribution. Then specialize to obtain the median.
Let \({{\rm{I}}_{\rm{i}}}\) be the input current to a transistor and \({{\rm{I}}_{\rm{0}}}\) be the output current. Then the current gain is proportional to\({\rm{ln}}\left( {{{\rm{I}}_{\rm{0}}}{\rm{/}}{{\rm{I}}_{\rm{i}}}} \right)\). Suppose the constant of proportionality is \({\rm{1}}\) (which amounts to choosing a particular unit of measurement), so that current gain\({\rm{ = X = ln}}\left( {{{\rm{I}}_{\rm{0}}}{\rm{/}}{{\rm{I}}_{\rm{i}}}} \right)\). Assume \({\rm{X}}\) is normally distributed with \({\rm{\mu = 1}}\) and\({\rm{\sigma = }}{\rm{.05}}\).
a. What type of distribution does the ratio \({{\rm{I}}_{\rm{0}}}{\rm{/}}{{\rm{I}}_{\rm{i}}}\) have?
b. What is the probability that the output current is more than twice the input current?
c. What are the expected value and variance of the ratio of output to input current?
Let X denote the number of flaws along a \({\bf{100}}\)-m reel of magnetic tape (an integer-valued variable). Suppose X has approximately a normal distribution with m \(\mu = 25\) and s \(\sigma = 5\). Use the continuity correction to calculate the probability that the number of flaws is
a. Between \({\bf{20}}\) and \({\bf{30}}\), inclusive.
b. At most \({\bf{30}}\). Less than \({\bf{30}}\).
What do you think about this solution?
We value your feedback to improve our textbook solutions.