Given :
Number of sample = n = 100
Number of success = X = 14
Sample proportion =
= X/n = 14/100 = 0.14
Significance level =
= 1-0.95 = 0.05
At 0.05 significance level the critical value of Z is
We are 95% confident that the Population proportion is between 0.072 and 0.208.
8) In a random sample of 100 commuters in a certain city, 14 regularly use public...
A survey of 350 residents of a certain city found that 82 used public transportation daily. You wish to find a 95% confidence interval for the true proportion of residents who use public transportation daily. What is the lower limit of the interval?
In a large metropolitan area, 25% of the commuters currently use the public transportation system, whereas the remaining 75% commute via automobile. The city has recently revitalized and expanded its public transportation system. It is expected that 6 months from now 30% of those who are now commuting to work via automobile will switch to public transportation, and 70% will continue to commute via automobile. At the same time, it is expected that 20% of those now using public transportation...
In a large metropolitan area, 25% of the commuters currently use the public transportation system, whereas the remaining 75% commute via automobile. The city has recently revitalized and expanded its public transportation system. It is expected that 6 months from now 40% of those who are now commuting to work via automobile will switch to public transportation, and 60% will continue to commute via automobile. At the same time, it is expected that 20% of those now using public transportation...
In a random sample of 100 homes in a certain city, it is found that 10 are heated by oil. (a) Find a 92% confidence interval for the true proportion of homes in the city that are heated with oil. (b) How large would the sample have to be in order to have a standard error that is 0.003 or lower?
i
am specifically looking at 4 and 5
1. A city official claims that the proportion of all commuters who are in favor of an expanded public transportation system is 50%. A newspaper conducts a survey to determine whether this proportion is different from 50%. Out of 225 randomly chosen commuters, the survey finds that 90 of them reply yes when asked if they support an expanded public transportation system. Test the official's claim at a = 0.05. 2. A...
To estimate the percentage of Binghamton residents who use public transportation, a simple random sample of 200 residents is taken. 75 of the people in the sample said they use public transportation, while the rest said they do not use public transportation. Find the SE for the percentage of Binghamton residents who use public transportation in our sample.
A sociologist finds that in a random sample of 142 U.S. teenagers, 112 regularly use social media to communicate with their friends and family. Use the sample to construct a 90% confidence interval for the proportion of teenagers who regularly use social media to communicate with their friends and family. What is the margin of error for the 90% confidence interval? Round to three decimal places.
A random sample of 432 voters revealed that 100 are in favor of a certain bond issue. A 95 percent confidence interval for the proportion of the population of voters who are in favor of the bond issue is
PLEASE ANSWER ALL AND WORK OUT!! 1. In a large metropolitan area, 25% of the commuters currently use the public transportation system, whereas the remaining 75% commute via automobile. The city has recently revitalized and expanded its public transportation system. It is expected that 6 months from now 30% of those who are now commuting to work via automobile will switch to public transportation, and 70% will continue to commute via automobile. At the same time, it is expected that...
26. In a random sample of 95 college students, 40 wished they would have chosen a different major. Use the following steps to construct a 95% confidence interval for the true proportion of all students who wished they would have chosen a different major. a. Find the number of sample values, n b. Find the sample proportion, B c. Find the critical z-score, 2/2 d. When calculated correctly, E = 0.0993. Construct a confidence interval for the population proportion, p....