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cloud1
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A simple random sample of 400 households is taken in a large city, and the number of cars in each sampled household is noted. The average number of cars in the sampled households is 1.8 and the SD is 1.3. Among the sampled households, 10% had no car.
PROBLEM 5
This problem is worth 1 point
An approximate 90% confidence interval for the average number of cars among households in the city goes from _____________________ to _______________________.
 one year ago
 one year ago
cloud1 Group Title
A simple random sample of 400 households is taken in a large city, and the number of cars in each sampled household is noted. The average number of cars in the sampled households is 1.8 and the SD is 1.3. Among the sampled households, 10% had no car. PROBLEM 5 This problem is worth 1 point An approximate 90% confidence interval for the average number of cars among households in the city goes from _____________________ to _______________________.
 one year ago
 one year ago

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ybarrap Group TitleBest ResponseYou've already chosen the best response.0
\[\mu \pm z\alpha\] you already have average and standard deviation, what is "z" corresponding to 90th confidence interval?
 one year ago

ybarrap Group TitleBest ResponseYou've already chosen the best response.0
The z that gives 90% confidence interval is 1.645: http://www.wolframalpha.com/input/?i=inverse+normal+z%3D1.645
 one year ago

ybarrap Group TitleBest ResponseYou've already chosen the best response.0
\[1.8\pm1.645*1.3\] \[Lower Range: 1.81.645*1.3\] \[Upper Range: 1.8+1.645*1.3\] Does this make sense?
 one year ago

Social Group TitleBest ResponseYou've already chosen the best response.0
@ybarrap What about this? An approximate 99% confidence interval for the percent of city households that have no car goes from _____________________% to ______________________%.
 one year ago

francoj22 Group TitleBest ResponseYou've already chosen the best response.0
6,14% to 13,86% ?
 one year ago

francoj22 Group TitleBest ResponseYou've already chosen the best response.0
Confidence Interval For Proportions
 one year ago
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