Final averages are typically approximately normally distributed with a mean of 72 and a standard deviation of 12.5. Your professor says that the top 8% of the class will receive an A, the next 20% a B, the next 42% a C, the next 18% a D, and the bottom 12% an F. a. What ...
April 16, 2015
1. In a study of heart disease in male federal employees, researchers classified 170 volunteer subjects according to their socioeconomic status (SES) and their smoking habits. SES categorized as high and low. Individuals were asked whether they were smokers or non-smoker. Here...
June 26, 2014
Q2_2: QUIZ 2, PROBLEM #2 The composite beam AB, of length L=2m, is free at A (x=0) and fixed at B (x=L) and is composed of a round cylindrical core of constant radius R0=1cm bonded inside a sleeve of thickness R0 (outer radius 2R0=2cm). The beam is loaded, as indicated, by a ...
July 26, 2013
Q2_1: QUIZ 2, PROBLEM #1 The shaft ABC is a solid circular cylinder of constant outer diameter 2R and length 3L. The shaft is fixed between walls at A and C and it is composed of two segments made of different materials. The left third of the shaft (AB) is composed of a linear...
July 26, 2013
I roll a pair of fair dice and compute the number of spots on the two sides facing up. Denote this total by X. The probability distribution of X is X Prob 2 1/36 3 2/36 4 3/36 5 4/36 6 5/36 7 6/36 8 5/36 9 4/36 10 3/36 11 2/36 12 1/36 The probability that X is an even number is
July 2, 2013
The incomes in a certain lg. population of college teachers have a normal distribution with a mean of $35,000 and st. dev. of $5000. Four teachers are randomly selected. What is the probability their average salary will exceed $40,000?
July 2, 2013
While standing at the edge of the roof of a building, you throw a stone upward with an initial speed of 7.53 m/s. The stone subsequently falls to the ground, which is 14.7 m below the point where the stone leaves your hand. At what speed does the stone impact the ground? How ...
May 2, 2013
A newspaper story on AIDS reports that an allele (R) confers complete resistance to HIV when homozygous and that 1% of the human population is resistant (RR). The story also states that 20% of the population carries one copy of the resistance allele (i.e., is heterozygous). Is...
April 7, 2013
I'm asked to find the arc length of the curve y=3+(1/2)sinh(2x) from 0 to 1. I figured it out up to the integral of sqr(1+(cosh(2x))^2) from 0 to 1, but I'm not sure how to go on to solve it.
April 3, 2012
The angular speed of an automobile engine is increased at a constant rate from 1200rev/min to 3000rev/min in 12s. How many revolutions does the engine make in this 12s interval? I worked it out to be 25200 rev. Is that right?
December 16, 2010
Improving Your Writing
This is more a comment,I am also in this boat, its very confusing if your only responsibility is Ruth and Jack why with all the names of four other employees. Why would they give you so much info you really don't need, and want you to make-up part of the scenario. Sounds ...
February 24, 2010
The probability is 1 in 4,000,000 that a single auto trip in the United States will result in a fatality. Over a lifetime, an average U.S. driver takes 50,000 trips. (a) What is the probability of a fatal accident over a lifetime? Explain your reasoning carefully. Hint: Assume...
September 16, 2008