An ACME Bearings manager wants to compare the average ball bearing size from two different machines. She suspects the mean diameter for bearing from machine 2 exceeds that of bearings from machine 1. She takes two independent, random samples of size 50, one from each machine. The mean and standard deviation of bearings taken from machine 1 are 3.302 mm and 0.051 mm. The mean and standard deviation of bearings taken from machine 2 are 3.355 mm and 0.050 mm. Run a hypothesis test consistent with her suspicions. Be sure to

a. check all necessary assumptions

(Independent random samples, large enough sample size- it will follow the normal distribution, both s.d is almost same.)

b. state the null and alternative hypotheses

H0 : mu2-mu1=0

Ha : mu2-mu1>0

I think mu2 - mu1 >0 because her suspect is that machine 2 exceeds that of from machine 1. However every answer is opposite such as mu2-mu1<0.

Would you please explain it?

c. calculate the test statistic and p-value

why we have to use the t-test instead of z-test?

d. state your conclusion in a complete sentence based of the p-value.

1.Give a brief overview of the topic linear programming.
2.Discuss the relevancy and application of LP to the career of an Executive director/Administrator of an assisted living building (a business environment that manage elderly people that need help with activities of daily living).
3.Give examples of how it is or can be used
Find a concrete example from recent history and write about it. I need to write 4 pages.

A sample of size 81 is taken from a population with unknown mean and standard deviation 4.5.  

In a test of H₀: μ = 5 vs. H_a: μ < 5, if the sample mean was 4, which of the following is true?

(i) We would fail to reject the null hypothesis at α = 0.01.

(ii) We would fail to reject the null hypothesis at α = 0.05.

(iii) We would fail to reject the null hypothesis at α = 0.10.

Suppose the lengths of the pregnancies of a certain animal are approximately normally distributed with mean (μ) = 227 days and standard deviation (σ) = 11 days

Complete parts​ (a) through​ (f) below.

​(f) What is the probability a random sample of size 20 will have a mean gestation period within 8 days of the​ mean?

The probability that a random sample of size 20 will have a mean gestation period within 8 days of the mean is ______________________ (do not round)

Data collected over a long period of time showed that 1 in 1000 high school students like mathematics. A random sample of 30,000 high school students was surveyed. Let X be the number of students in the sample who like mathematics

a) What is the probability distribution of X?

b) What distribution can be used to approximate the distribution of X? Explain.

c) Find the approximate probability of observing a value of X equal to 40 or more?

d) Find the approximate probability of observing a value of X between 35 and 40 inclusive ?

Based on a survey, workers in Ontario earn an average of $60,000 per year with a known standard deviation of $6000. In an attempt to verify this salary level, a random sample of 36 workers in Ontario was selected. Let X represent the mean salary of these 36 workers.

a) Describe the sampling distribution of X.

b) Calculate the probability that X is between 58,500 and 63,000.

c) What is the 90th percentile for X.

From driverless cars to a workplace staffed by robots, automation has the potential to reshape many facets of American life. The large majority of Americans (87%) would favor a requirement that all driverless vehicles have a human in the driver's seat who can take control of the vehicle in the event of an emergency, while 56% of U.S. adults say that they would not ride in a driverless vehicle.† If these figures are correct, what is the probability that in a sample of n = 100 U.S. adults, the sample proportion p̂ of adults who would not ride in a driverless vehicle falls between 54% and 64%? (Round your answer to four decimal places.)

Police response time to an emergency call is the difference between the time the call is first received by the dispatcher and the time a patrol car radios that it has arrived at the scene. Over a long period of time, it has been determined that the police response time has a normal distribution with a mean of 8.9 minutes and a standard deviation of 1.7 minutes. For a randomly received emergency call, find the following probabilities.
A) the response time is between 5.25 and 12.65 minutes.
B) the response time is 6.15 to 8.65 minutes.
C) the response time is anywhere from 11.65 to less than 12.85 minutes.
D) the response time is anywhere greater than 6.85 to 16.25 minutes.

Is there a way to make a pivot table from a data set to show the following:

- make gender the columns (one column for male and one for female)
- rows are age increments (18 - 30, 31 - 40, 41 - 50, 51 - 60, 61 - 70)
- information provided within the pivot table is the average salary of everyone within the age increment (for example, I want to find the average salary of a male between the ages of 41 - 50, or the average salary of a female between the ages of 31 - 40). I'm not able to provide a data set because it's too large, but if instructions can be provided, that would be amazing!

For each case, indicate whether the count response would be better model with Poisson or a binomial distribution

(a) You randomly visit 12 married couples who have been married for 20 years and count the number that have no children.

(b) You visit 12 married couples with children, and count the number of times in the past year that each family has had visited the hospital emergency room.

(c) During an hour of studying, you count the number of times you get a text.

(d) During an hour of studying, you count the number texts that you decide to reply to.

(e) Suppose you arrive at the bus loop every Monday morning at 9:00 for 14 consecutive weeks. You count the number of buses each week that fill up before you get on one.

(f) Suppose you arrive at the bus loop every Monday morning at 9:00 for 14 consecutive weeks. You count the number of times your friend is in line ahead of you when you arrive.

(g) For a full term, you count the number of typos on a particular professor’s slides in each lecture.

(h) For a full term, you count the number of midterms that have at least one typo on them.

(i) Professor counts the number of students who are asleep at the mid-point of a particular lecture.

home / study / math / statistics and probability / statistics and probability questions and answers / dr. francis has determined the sequence of a gene from four fish species. below, it is described ... Question: Dr. Francis has determined the sequence of a gene from four fish species. Below, it is described ... Dr. Francis has determined the sequence of a gene from four fish species. Below, it is described a segment of the sequence of this gene for the 4 species (NA-Sp, North Atlantic species; SA-Sp, South Atlantic species; Pc-Sp, Pacific species; Md-Sp,Mediterranean species). The letters below the codons are the amino acids encoded.

Healthy subjects aged 18 to 40 participated in a study of eating habits. Subjects were given bags of potato chips and bottled water and invited to snack freely. Was there a difference between men and women in the number of potato chips consumed? Here are the data on grams of potato chips consumed.

We are interested in calculating a 90% confidence interval for the difference in mean number of potato chips consumed between men and women. Without using software, what is the appropriate critical value to use in the calculation of the confidence interval? Hint: Use the approximation used in the module for determining the approximate degrees of freedom.