A researcher found that a cigarette smoker smokes on average 31 cigarettes a day. She feels that this average is too high. She selected a random sample of 15 smokers and found that mean number of cigarettes they smoked per day was 28. The sample standard deviation was 2.4. At Alpha αequals 0.05 is there enough evidence to support her claim?Assume that the population is approximately normally distributed.
A researcher found that a cigarette smoker smokes on average 31 cigarettes a day. She feels...
The amounts of nicotine in a certain brand of cigarette are normally distributed with a mean of 0.962 g and a standard deviation of 0.316 g. The company that produces these cigarettes claims that it has now reduced the amount of nicotine. The supporting evidence consists of a sample of 41 cigarettes with a mean nicotine amount of 0.893 g. Assuming that the given mean and standard deviation have NOT changed, find the probability of randomly selecting 41 cigarettes with...
(2) A state executive claims that the average cost of tuition at public colleges is $5700. A researcher wishes to test the claim that this cost is greater than $5700. She selects a random sample of 36 public colleges and finds the mean to be $5950.The population standard deviation is $659. Is there enough evidence to support the claim that the cost of tuition is greater than $5700 at a 0.05?
minitab codes Exercise #1 Revenue of Large Businesses: A researcher estimates that the average revenue of the largest businesses in the United States is greater than $24 billion. A sample of 50 companies is selected, and the revenues (in billions of dollars) are in the table below. At a 0.05, is there enough evidence to support the researcher's claim? Answer the following questions from the paragraph: a. What is the null hypothesis in symbolic form. Example: mu - 35 Answer:...
Assume that a simple random sample has been selected from a normally distributed population and test the given claim. State the final conclusion that addresses the original claim and select three correct choices. A machine dispenses a liquid drug into bottles in such a way that the standard deviation of the contents is 81 milliliters. A new machine is tested on a sample of 24 containers and the standard deviation for this sample group is found to be 26 milliliters....
17 and 18 please. Thank you. gleater than 700 pounds? DIe 81 31 female giraffes are chosen. The mean height is found to be 15 feet. Assume that the population standard deviation for the height of female giraffes is。 5 feet. Calculate the 85% confidence interval of for population mean height of female giraffes. 16) A sample of 21 male giraffes are chosen. The mean height is found to be 17.5 feet. The standard deviation of the sample is found...
l 37) A researcher would like to determine whether a new tax on cigarettes has had any effect on people's behavior. During the year before the tax was imposed, stores located in rest areas on the state thruway reported selling an average of u = 410 packs per day with s = 60. The distribution of daily sales was approximately normal. For a sample of n = 9 days following the new tax, the researcher found an average of M...
A researcher studies water clarity at the same location in a lake on the same dates during the course of a year and repeats the measurements on the same dates 5 years later. The researcher immerses a weighted disk painted black and white and measures the depth (in inches) at which it is no longer visible. The collected data is given in the table below. Complete parts (a) through (c) below. Observation 1 2 3 5 6 Date 125 3/195/307/39/13...
A researcher studies water clarity at the same location in a lake on the same dates during the course of a year and repeats the measurements on the same dates 5 years later. The researcher immerses a weighted disk painted black and white and measures the depth (in inches) at which it is no longer visible. The collected data is given in the table below. Complete parts (a) through (c) below. Observation 1 2 3 5 6 Date 1/25 3/195/30...
Lung Cancer & Smoking Case Study A causal relationship between cigarette smoking and lung cancer was first suspected in the 1920s on the basis of clinical observations. To test this apparent association, numerous epidemiologic studies were undertaken between 1930 and 1960. Two studies were conducted by Richard Doll and Austin Bradford Hill in Great Britain The first was a case-control study begun in 1947 comparing the smoking habits of lung cancer patients with the smoking habits of other patients. The...
Question 3 A researcher is interested in the relationship between the birth weights of infants and mothers' smoking habits. He uses the birth weight of an infant (ounces) and the average number of cigarettes the mother smokes per day during the pregnancy as the dependent and independent variables, y and x, respectively. Using a sample of size (1388 the following model is obtained by the method of least squares: y-119.770.514.x (3.15) (0.13) SE e the figures in brackets are the...