Suppose that the duration of a particular type of criminal trial is known to have a mean of 21 days and a standard deviation of 7 days. We randomly sample 9 trials.
In words,
$\mathrm{\Sigma X}=$
$\mathrm{\Sigma X}\text{~}$
Find the probability that the total length of the 9 trials is at least 225 days.
90 percent of the total of 9 of these types of trials will last at least how long?
According to the Internal Revenue Service, the average length of time for an individual to complete (record keep, learn, prepare, copy, assemble and send) IRS Form 1040 is 10.53 hours (without any attached schedules). The distribution is unknown. Let us assume that the standard deviation is 2 hours. Suppose we randomly sample 36 taxpayers.
In words,
$X=$
In words,
$\overline{X}=$
$\overline{X}\text{~}$
Would you be surprised if the 36 taxpayers finished their Form 1040s in an average of more than 12 hours? Explain why or why not in complete sentences.
Would you be surprised if one taxpayer finished his Form 1040 in more than 12 hours? In a complete sentence, explain why.
Suppose that a category of world class runners are known to run a marathon (26 miles) in an average of 145 minutes with a standard deviation of 14 minutes. Consider 49 of the races.
Let
$\overline{X}=$ the average of the 49 races.
$\overline{X}\text{~}$
Find the probability that the runner will average between 142 and 146 minutes in these 49 marathons.
Find the 80th percentile for the average of these 49 marathons.
Suppose that the length of research papers is uniformly distributed from 10 to 25 pages. We survey a class in which 55 research papers were turned in to a professor. The 55 research papers are considered a random collection of all papers. We are interested in the average length of the research papers.
In words,
$X=$
$X\text{~}$
${\mu}_{X}=$
${\sigma}_{X}=$
In words,
$\overline{X}=$
$\overline{X}\text{~}$
In words,
$\mathrm{\Sigma X}=$
$\mathrm{\Sigma X}\text{~}$
Without doing any calculations, do you think that it’s likely that the professor will need to read a total of more than 1050 pages? Why?
Calculate the probability that the professor will need to read a total of more than 1050 pages.
Why is it so unlikely that the average length of the papers will be less than 12 pages?
The length of songs in a collector’s CD collection is uniformly distributed from 2 to 3.5 minutes. Suppose we randomly pick 5 CDs from the collection. There is a total of 43 songs on the 5 CDs.
In words,
$X=$
$X\text{~}$
In words,
$\overline{X}\text{=}$
$\overline{X}\text{~}$
Find the first quartile for the average song length.
The IQR (interquartile range) for the average song length is from _______ to _______.
Solve for the first variable in one of the equations, then substitute the result into the other equation.
Point For:
(6111,4111,−411)(6111,4111,-411)
Equation Form:
x=6111,y=4111,z=−411x=6111,y=4111,z=-411
An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
why surface tension is zero at critical temperature
Shanjida
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
s.
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
1 It is estimated that 30% of all drivers have some kind of medical aid in South Africa. What is the probability that in a sample of 10 drivers: 3.1.1 Exactly 4 will have a medical aid. (8) 3.1.2 At least 2 will have a medical aid. (8) 3.1.3 More than 9 will have a medical aid.