The average life of a battery used in newly designed electric cars is 150 hours with a standard deviation of 20hours. Suppose these values are true for all batteries of this type so that these values...
The average life of a battery used in newly designed electric cars is 150 hours with a standard deviation of 20hours. Suppose these values are true for all batteries of this type so that these values...
Based on a report, 55% of the voters believe that the nation's current economic problems are the result of recession that started during the Bush administration. A new Rasmussen Reports national telephone...
A study about the students graduating within 4 years of their entrance to the universities indicated that 62% of the students do not graduate within 4 years. Suppose a random sample of 500 students...
A quality engineer is interested in estimating the mean time required to assemble a bat code scanner. If the engineer wishes to be 95% confident that the error is estimating the mean time is less...
The Nielson Company reported that as of the third quarter of 2010, 28% of U.S. mobile subscribers now have smart phones. The growing popularity of smart phones has accelerated the adoption rate. Among...
The length of time what a space rocket component functions is approximately normally distributed. A sample of 20 of these components showed a mean of 900hours with a standard deviation of 87 hours...
standard deviation of 2.5 inches. In order to serve in the U.S. Army, women must be between 58 inches and 80 inches tall. What percentage of women are ineligible to serve based on their height? I...
A colleague of mine needs to analyze the results of a study he did not design. It's an RCBD with four reps. Most of the treatments are included in a two-factor design with two nitrogen application...
The production manager of a bottling plant has acquired new machines to fill beverage cans. The machines are used to fill 16 ounce cans. If the filling machine is working properly, the mean fill volume...
When σ is unknown and the sample is of size n ≥ 30, there are two methods for computing confidence intervals for μ. Method 1: Use the Student's t distribution with d.f. = n − 1. This is the...
Do you want to own your own candy store? Wow! With some interest in running your own business and a decent credit rating, you can probably get a bank loan on startup costs for franchises such as Candy...
what is the formula to calculate the confidence interval for The difference of two population means μ1 − μ2 when it is no longer reasonable to assume that the population variances are not far too...
What price do farmers get for their watermelon crops? In the third week of July, a random sample of 38 farming regions gave a sample mean of x = $6.88 per 100 pounds of watermelon. Assume that σ is...
The owner of a large shopping center wants to survey a sample of 12 store owners and ask them if they would stay open one hour late one evening for a charity event. He divides the stores into...
Human body temperatures are normally distributed with a mean of 98.20°F and a standard deviation of 0.62°F. If 19 people are randomly selected, find the probability that their mean body temperature...
?56% of men consider themselves professional baseball fans. You randomly select 10 men and ask each if he considers himself a professional baseball fan. Find the probability that the number who consider...
The player is set on random play, so selections are played randomly and can be repeated . Determine the probability of each of the following outcomes. (a) The first four selections are all jazz (b)...
Sixty-four randomly selected adults who buy books for general reading were asked how much they usually spend on books per year. The sample produced a mean of $1450 and a standard deviation of $300...
It is estimated that 3.2% of the general population will live past their 90th birthday. In a graduating class of 737 high school seniors, find the following probabilities. (Round your answers to four...
The claim is that the IQ scores of statistics professors are normally? distributed, with a mean greater thangreater than 118. A sample of 12 professors had a mean IQ score of 119with a standard deviation...