A study is conducted on a group of HIV-infected individuals that exhibit signs of a newly-defined syndrome. A p-value was calculated (using a one-samplet test) to test the Ho that the mean lactate level was equal to r (versus Ha not equal to 5). This yielded a p = 0.074. Construct 2-tailed 90% and 95% confidence intervals for the mean lactate level in this population. Which statement below describes your findings?
| a. |
Both CIs would include 5. |
|
| b. |
Neither CI would include 5. |
|
| c. |
The 95% CI would include 5; however, the 90% CI would not. |
|
| d. |
The 90% CI would include 5; however, the 95% CI would not. |
If p-value is less than alpha i.e. significance level, we should reject H0. If we reject H0, then the confidence interval should not contain the population mean
Option-B) Neither CI would include 5.
A study is conducted on a group of HIV-infected individuals that exhibit signs of a newly-defined...
2. Suppose that you have been assigned to study HIV-infected individuals that exhibit signs of the newly-defined Ascending Neuromuscular Weakness Syndrome (ANWS). You find that there are very many hospitals of this syndrome and that there are no obvious characteristics that suggest different signs of this syndrome. Your resources will permit an experiment with adequate replication of six treatments. How will you select infected individuals?
The mean serum-creatinine level measured in 12 patients 24 hours after they received a newly proposed antibiotic was 1.2 mg/dL. 1. If the mean and standard deviation of serum creatinine in the general population are 1.0 and 0.4 mg/dL, respectively, then, using a significance level of 0.05, test whether the mean serum-cre level in this group is different from that of the general population. 2. What is the p-value for the test? 3. Suppose t1.52 and a on one-sample t...
The output below is for a t-test for the hypothesis: Individuals
living in bad neighborhoods commit more crime than those living in
good neighborhoods. The data in the Group Statistics section
provides you with the average number of crimes committed by
individuals living in good and bad neighborhoods and the standard
deviation of this same variable. The findings of significance are
located in the Independent Samples Test section. Pay particular
attention to the "t" column and the "Sig (2-tailed)"column. The...
A researcher wanted to study the effect of a newly developed gasoline additive (Additive X) on automobile mileage (miles per gallon, MPG). To gather information, a random sample of cars has been selected. For each car, the MPG was measured both when gasoline with Additive X is used and when gasoline without Additive X is used. The order of the two treatments (with Additive X versus without Additive X) was randomized and care was taken so that there was no...
[33] The manager of computer operations of a large company wants to study computer usage of two departments within the company - the accounting department and the research department. A random sample of five jobs from the accounting department in the past week and six jobs from the research department in the past week are selected, and the processing time in seconds) for each job is recorded: Department Processing Time (seconds) Accounting 93 8 712 Research 4 13 10 9...
Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The 200 students in group 1 had a mean score of 26.2 with a standard deviation...
1. Newborn weight. A study takes a SRS from a population of
full-term infants. The standard deviation of birth weights in this
population is 2 pounds. Calculate 95% confidence intervals for μ
for samples in which:
a) n = 81 and = 7.0 pounds
b) n = 9 and = 7.0 pounds
c) Which sample provides the most precise estimate of the mean
birth weight?
d) Interpret the CI you computed in part a).
2. P-value and confidence interval. A...
Question 1 A study was conducted to estimate μ, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be σ = 3.6 hours. A similar study conducted a year earlier estimated that μ, the mean number of weekly hours that U.S. adults use computers at home,...
Reliance on solid biomass fuel for cooking and heating exposes many children from developing countries to high levels of indoor air pollution. An article presented information on various pulmonary characteristics in samples of children whose households in India used either biomass fuel or liquefied petroleum gas (LPG). For the 754 children in biomass households, the sample mean peak expiratory flow (a person's maximum speed of expiration) was 3.2 V/s, and the sample standard deviation was 1.2. For the 753 children...
1. You measure 42 textbooks' weights, and find they have a mean weight of 47 ounces. Assume the population standard deviation is 3.5 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight. Give your answers as decimals, to two places 2.If n=16, ¯xx¯(x-bar)=43, and s=13, construct a confidence interval at a 99% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place. 3.SAT scores are...