There are researchers who want to know if M poisoning in mice is less extreme in...

There are researchers who want to know if M poisoning in mice is less extreme in males. An SRS of one hundred male mice and an independent SRS of one hundred female mice are obtained. The male mice had a sample mean of thirty-nine and a sample standard deviation of eight. The female mice had a sample mean and standard deviation of 40 and 10, respectively. Let u₁ represent the true mean response for the males and u₂ represent the true mean response of the females.

a) You must find a point estimate for the difference that there is between the two population means.

b) Find a ninety-nine percent confidence interval for u1-u2 and explain your results.

Solutions

Expert Solution

Point estimate of difference = 39 - 40 = -1

SE = sqrt[ (s12/n1) + (s22/n2) ]
(s12/n1)   0.6400
(s22/n2)    1.0000
SE   1.2806

DF = (s12/n1 + s22/n2)2 / { [ (s12 / n1)2 / (n1 - 1) ] + [ (s22 / n2)2 / (n2 - 1) ] }
[ (s12 / n1)2 / (n1 - 1) ]            0.004
[ (s22 / n2)2 / (n2 - 1) ]           0.01
(s12/n1 + s22/n2)2           2.69
DF =    189

t value at 99% = 2.602

CI = (x1- x2) +/- t *sqrt(s1^2/n1+s2^2/n2)
= ( 39 -40) +/ 2.602 *sqrt(8^2/100 + 10^2/100)
= (-4.3325 , 2.3325 )

The 99% CI is (-4.3325 , 2.3325 )

orchestra answered 1 year ago

Next > < Previous

Related Solutions

Poisoning by the pesticide DDT causes tremors and convulsions. In a study of DDT poisoning, researchers...

Poisoning by the pesticide DDT causes tremors and convulsions. In a study of DDT poisoning, researchers fed several rats a measured amount of DDT. They then measured electrical characteristics of the rats' nervous system that might explain how DDT poisoning causes tremors. One important variable was the "absolute refractory period"—the time required for a nerve to recover after a stimulus. This period varies Normally. Measurements of the absolute refractory period, in milliseconds, for four rats were 1.7, 1.8, 1.9, and...

Researchers want to know if playing violent video games increases aggression levels. They know that the...

Researchers want to know if playing violent video games increases aggression levels. They know that the typical teenager scores an average of μ = 4 on a test of aggression. To evaluate their hypothesis, they take a random sample of n = 5 teenagers and have them play violent video games for two hours. After playing the games the teenagers then are measured with the aggression test, resulting in the following scores: X 7 6 4 5 5 (a) Identify...

Researchers working for Kaiser want to know if there is a relationship between smoking and diabetes....

Researchers working for Kaiser want to know if there is a relationship between smoking and diabetes. They sample 900 patients at random from the population of patients who are 18 and older. In the sample, there are 145 smokers. Of these, 54 have no diabetes, 72 have pre-diabetes, and 19 have diabetes. Among the nonsmokers, 527 have no diabetes, 160 have pre-diabetes, and 68 have diabetes. (a) What is the null hypothesis the researchers might want to test, and what...

Researchers want to examine whether or not there is a difference in birthweight for mothers who...

Researchers want to examine whether or not there is a difference in birthweight for mothers who smoke and mothers who do not smoke. Their alternate hypothesis is Ha: μ1 ≠ μ2.They collect smoking status and birthweight information for 189 pregnancies. For your convenience, I have prepared an Excel file with the data Nonsmoker Smoker 2877 2600 3062 2665 3234 2769 3459 2769 3473 2906 3586 2992 3600 3076 3614 3076 3827 3132 3941 3317 4111 3374 2100 3629 2353 3637...

A team of researchers has developed a new weight loss supplement. They want to know if...

A team of researchers has developed a new weight loss supplement. They want to know if patients who use the new supplement for four weeks lose any weight. The supplement has some minor side effects including mild headaches and achiness. If the researchers obtain evidence of weight loss they will proceed to produce the supplement commercially and sell it for a large profit. If they do not obtain evidence of weight loss, the project will be ended. State the null...

To understand the implications of expanding health coverage,researchers want to know if people with health...

To understand the implications of expanding health coverage, researchers want to know if people with health insurance use more health care than do people without it. To test this, they leveraged an administrative lottery that randomly assigned individuals to either receive public health care or not. Using the data below on the number of medical interactions (e.g., hospital visits or doctor appointments), test whether individuals with health insurance use health services differently than do those without it (alpha=0.1, two tails).No...

A team of researchers have developed a new weight loss drug. They want to know if...

A team of researchers have developed a new weight loss drug. They want to know if patients who use the new drug for two weeks lose any weight. The drug has some minor side effects including mild headaches and achiness. If the researchers obtain evidence of weight loss they will proceed to produce the drug commercially and sell it for a large profit. If they do not obtain evidence of weight loss they will end the project. [70 points] What...

Researchers want to know if there are significant differences in life satisfaction based on college students'...

Researchers want to know if there are significant differences in life satisfaction based on college students' overall financial status. In a Word document go thru the 5 steps for hypothesis testing and upload your answer here. life satisfaction financial status 35 3 34 2 31 3 31 3 28 3 28 3 28 2 21 2 29 3 30 2 30 3 29 3 29 3 15 2 30 2 30 2 29 3 20 3 29 2 35 3...

2 Systolic Blood Pressure & Heart Rate Researchers want to know if there is a relationship...

2 Systolic Blood Pressure & Heart Rate Researchers want to know if there is a relationship between systolic blood pressure and heart rate in the population of all ICU patients. They collected data from a sample of 200 ICU patients and computed a correlation of r = -0.057 between systolic blood pressure and heart rate. StatKey was used to construct a 95% confidence interval of [-0.212, 0.098] for the population correlation. If researchers wanted to conduct a hypothesis test to...

Did lead poisoning bring down ancient Rome? Some researchers have questioned whether lead poisoning contributed to...

Did lead poisoning bring down ancient Rome? Some researchers have questioned whether lead poisoning contributed to the downfall of the Roman Empire. There are several published papers explaining the potential evidence and their importance. You need to search different resources and discuss if this could be true or not? And why?

Subjects