miscellaneous
The Wall Street Journal reported that Coca-Cola sells about 46% of all soda pop consumed worldwide. Suppose your observation of a random sample of 216 students who selected a soft drink from school vending machines showed that 81 chose a Coke product. Does this indicate that the soft drink market share of Coca-Cola at the school is less than 46%? What are the hypothesis statements?
Ho: p = 0.46
Ha: p < 0.46
Sixty-five clerical workers at a large financial service organization participated in a health risk analysis. The sample mean systolic blood pressure and standard deviation were 111.63 and 11.94, respectively. Using a 0.10 significance level, is there sufficient evidence to conclude that the mean systolic pressure for all clerical workers at this business exceeds 110? What are the hypothesis statements?
Ho: 'mu' = 110
Ha: 'mu' > 110
In a random sample of 500 people aged 20-24, 110 were smokers. In a random sample of 450 people aged 25-29, 85 were smokers. Test the claim that the proportion of smokers in the two age groups is different. Use a significance level of 0.01. What are the hypothesis statements?
Ho: py = po
Ha: py not equals to po
A researcher wants to know if eating apples makes people smarter. Her hypothesis is that people who eat apples will have higher intelligence than people who do not eat apples.
What are the hypothesis statements for this situaion?
See the white boar.
The Wall Street Journal reported that Coca-Cola sells about 46% of all soda pop consumed worldwide. Suppose your observation of a random sample of 216 students who selected a soft drink from school vending machines showed that 81 chose a Coke product. Does this indicate that the soft drink market share of Coca-Cola at the school is less than 46%? What is the p-value?
p-value = 0.0061
Sixty-five clerical workers at a large financial service organization participated in a health risk analysis. The sample mean systolic blood pressure and standard deviation were 111.63 and 11.94, respectively. Using a 0.10 significance level, is there sufficient evidence to conclude that the mean systolic pressure for all clerical workers at this business exceeds 110? What is your decision?
Retain Ho
In a random sample of 500 people aged 20-24, 110 were smokers. In a random sample of 450 people aged 25-29, 85 were smokers. Test the claim that the proportion of smokers in the two age groups is different. Use a significance level of 0.01. What is your decision?
Retain Ho
Occasionally warning flares of the type contained in automobile emergency kits fail to ignite. A consumer group wants to investigate the company's claim that 10% of their flares fail to ignite. They think that this percentage is higher. What is a type 1 error in this situation?
The consumer group finds that the percentage of flares that do not ignite is higher than 10% when actually it is 10%.
The Wall Street Journal reported that Coca-Cola sells about 46% of all soda pop consumed worldwide. Suppose your observation of a random sample of 216 students who selected a soft drink from school vending machines showed that 81 chose a Coke product. Does this indicate that the soft drink market share of Coca-Cola at the school is less than 46%?What is your decision?
Sixty-five clerical workers at a large financial service organization participated in a health risk analysis. The sample mean systolic blood pressure and standard deviation were 111.63 and 11.94, respectively. Using a 0.10 significance level, is there sufficient evidence to conclude that the mean systolic pressure for all clerical workers at this business exceeds 110? What is the summary statement?
The sample data suggests that the mean systolic pressure for all clerical workers at this business does not significantly exceed 110.
In a random sample of 500 people aged 20-24, 110 were smokers. In a random sample of 450 people aged 25-29, 85 were smokers. Test the claim that the proportion of smokers in the two age groups is different. Use a significance level of 0.01. What is the summary statement?
The sample data suggests that the proportion of smokers in the two age groups are not significantly differernt.
Occasionally warning flares of the type contained in automobile emergency kits fail to ignite. A consumer group wants to investigate the company's claim that 10% of their flares fail to ignite. They think that this percentage is higher. What is a type 2 error in this situation?
The consumer group determines that the percentage of flaires that fail to ignite is 10% when actually it is greater than 10%.
The Wall Street Journal reported that Coca-Cola sells about 46% of all soda pop consumed worldwide. Suppose your observation of a random sample of 216 students who selected a soft drink from school vending machines showed that 81 chose a Coke product. Does this indicate that the soft drink market share of Coca-Cola at the school is less than 46%? What is your summary statement?
The sample data suggests that the share of Coca-Cola in soft drink market is less than 46% at this school.
A company would like to estimate the average time of first sprinkler activation (in seconds) for a series of tests of fire-prevention sprinkler systems that use aqueous film-forming foam. Use the data below to construct a 90% confidence for the average time. Search for Sprinkler Activation in StatCrunch.
(26.9 seconds, 30.7 seconds)
A recent study of 3100 randomly selected children found 713 of them deficient in vitamin D. Construct a 99% confidence interval for the true proportion of children that are deficient in vitamin D.
(0.211, 0.250)
When a person creates a confidence interval for a proportion what are they are trying to estimate?
p-hat
p
x-bar
"mu"
p - population proportion
A pollster wishes to estimate the true proportion of U.S. voters who think marijuana should be legalized. How many voters must be surveyed in order to be 90% confident that the true proportion is estimated to within 3%?
752 voters
An educational research group would like to estimate the mean number of hours that full time college students study each week. How many students must they survey to be 99% confident that the margin of error is 0.75 hours? Assume that the population standard deviation is 2 hours.
48 students
A recent study of 3100 randomly selected children found 713 of them deficient in vitamin D. Construct a 99% confidence interval for the true proportion of children that are deficient in vitamin D. Write a summary statement for this situation.
We are 99% confidenct that the true proportion of children that are deficient in vitamin D is between 0.211 and 0.250.
A 99% confidence interval for the mean commute distances for CCBC students is (0.25 miles, 5.45 miles).
What is x-bar (the point estimate)?
2.85 miles