Suppose that the scores of architects on a particuloart creativity test are normallly distributed. What percentage of archietects have z scores above: a above .10 b below.10 c.above.20 d.below .20 e.above 1.10 f.below 1.10 g above-.10 h below-.10
1. Heights of Presidents. With a height of 67 in., William McKinley was the shortest president of the past century. The presidents of the past century have a mean height of 71.5 in. and a standard deviation of 2.1 in. a. What is the difference between McKinley's height and the mean height of presidents from the past century?
Many elementary school students in a school district currently have ear infections. A random sample of children in two different schools found that 16 of 42 at one school and 21 of 36 at the other had this infection. At the .05 level of significance, is there sufficient evidence to conclude that a difference exists between the
A Survey is conducted to determine the mean number of minutes per day that teens between the age of 16 and 18 spend watching television per day. A previous study showed that the population standard deviation was 21.5 minutes. The organization selected a random sample of n = 200 teens between the ages of 16 and 18 and recorded th
I am working through an online problem (UoP ALEKS training) regarding Normal Distribution. I understand how the system works the problem up until the end. It says: Using the calculator, we have: P(X<0)=P(Z<-1.0833) They obtain a value of 0.1393 I have put in the value of -1.0833 for the z value, but it says that is
Question: Suppose the federal government proposes to give a substantial tax break to automakers producing midsize cars that get a mean mileage exceeding 31 mpg. A sample of 49 midsize cars showed a mean of 31.5 mpg, with a standard deviation 0.8. [Use Excel- Megastat, hypothesis tests, the mean v hypothesized value, a z-test or
Please help with the following problem. Media Disk, Inc. duplicates over a million 3.5" floppy disks each year by copying masters to stacks of blank disks. The company buys its blank stock from two different suppliers, A and B. The manager has decided to check each supplier's stock by counting the rejected disks in the next
Given that z is a standard normal random variable and that the area to the right of z is 0.1949, then the value of z must be A) 0.51 B) -0.51 C) 0.86 D) -0.86 Your high school graduating class had 564 members. Thirty-three percent of these are expected to attend college. The probabili
If a student had a z-score of 1, what would be the raw score (rating)? If a student had a z-score of 1, what percentage of the participants would be expected to rate the product higher than he/she did? If a student gave a rating of 75, what would be the z-score? What is the probability that a rating is bel
In a particular region of Cape Cod, it is known that lobstermen trap on average of 32 pounds of lobster per day with a standard deviation of four pounds. If a random sample of 30 lobster fishermen is selected, what is the probability that their average catch is less than 31.5 pounds? Round your answer to four decimal places.
Mrs. Smith's reading class can read a mean of 175 words per minute with a standard deviation of 20 words per minute. The top 3% of the class is to receive a special award. What is the minimum number of words per minute a student would have to read in order to get the award? Place your answer, rounded to the nearest whole numbe
On a test whose distribution is approximately normal with a mean of 50 and a standard deviation of 10, the results for three students were reported as follows: Student Opie has a T-score of 60. Student Paul has a z-score of -1.00. Student Quincy has a z-
Can people really identify their favorite brand of cola? Volunteers tasted Coca-Cola Classic, Pepsi, Diet Coke, and Diet Pepsi, with the results shown below. At α = .05, is the correctness of the prediction different for the two types of cola drinkers? Could you identify your favorite brand in this kind of test? Since it is
Individual scores of a placement examination are normally distributed with a mean of 84.2 and a standard deviation of 12.8. If the score of an individual is randomly selected, find the probability that the score will be less than 90.0. If a random sample of size n = 20 is selected, find the probability that the sample mean
A normal distributed population has a mean of 250 pounds and a standard deviation of 10 pounds. Given n = 20, what is the probability that this sample will have a mean value between 245 and 255 pounds?
Two banks in the Miami, Fl area compete for credit card customers. In order to select the better bank, we want to test whether there is a difference in the proportion of times a customer is able to reach the Customer Service representative in less than 2 minutes. We have called the first bank 500 times, and were able to speak to
In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 25 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 5 accidents. At α = .01, did the yellow fire trucks have a significantly lo
Please see attachment. In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At á = .01, did the yellow fire trucks h
A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations. (b) Calculate a p-value and interpret it.
Please provide a step by step proces and explanation. I am not understanding how these answers are derived for this question. Results from previous studies showed 79% of all high school seniors from a certain city plan to attend college after graduation. A random sample of 200 high school seniors from this city reveals tha
In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At α = .01, did the yellow fire trucks have a significantly lo
The mean employee turn over at Ms. Jameelah's employment of 280 employees hired for the different new position each year is 20 with standard deviation of 4.6. It is now assumed that because of the down turn in the economy, the turn over has decreased to less than 20 in average. A random sample of 90 employees from 280 total show
A researcher was interested in determining whether corporate executives who exercised regularly scored lower than corporate executives in general on a scale of stress symptoms. For corporate executives in general, the average on this test is 80 with a standard deviation of 12. The researcher then measured 20 executives who exerc
9.32 A manufacturer of salad dressing uses machines to dispense liquid ingredients into bottles that move along a filling line. The machine that dispenses dressings is working properly when the mean amount dispensed is 8 ounces. The population standard deviation of the amount dispensed is different from 8 ounces. Suppose that th
Using the data set below, can you tell me if any variable for any observation is appropriate for the calculation of a z score. If it is please explain how to calculate and interpret a z score on that variable. If it is not please tell me why it isn't appropriate for this data set. Title Year Rating Budget ($) Gross ($) L
It has been reported that 10.3% of U.S. households do not own a vehicle, with 34.2% owning 1 vehicle, 38.4% owning 2 vehicles, and 17.1% owning 3 or more vehicles. The data for a random sample of 100 households in a resort community are summarized in the frequency distribution below. At the 0.05 level of significance, can we r
Assume that replacement time for TVs are normally distributed with a mean of 8.2 years and a standard deviation of 1.1 years. The probability a randomly selected TV will have replacement time less than 5.5 years to be .0071. Determine the time length of a warranty such that only 3.5% of the TVs would be replaced before the w
At one university, the distance to students' home is normally distributed with a mean of 200 miles and a standard deviation of 25 miles. a. what is the probability of a student living more than 241.25 miles from the school? b. what % of students live between 180 and 220 miles from the school?
What is meant by the z score. Where does that come from?
A furniture store claims that a specially ordered product will take, on average,28 = days (4 weeks) to arrive. The standard deviation of these waiting times is 7 days. We suspect that the special orders are taking longer than this. To test this suspicion, we track a random sample of 80 special orders and find that the orders