Confidence Intervals

#1
The State of California wishes to estimate the proportion of drivers who use their cell phones while driving. In a random sample of 250 California drivers 94 of these drivers stated that they used their cell phones while driving. Construct a 96% confidence interval for the true proportion of California drivers who use their cell phones while driving.
Choose one answer.

a. (0.3328, 0.4192)

b. (0.3248, 0.4272)

c. (0.3132, 0.4388)

d. None of the these are correct.



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According to my calculations I get b. (0.3248, 0.4272), but I just wanted to make sure I was correct.

THanks
 

Martingale

TS Contributor
#2
The State of California wishes to estimate the proportion of drivers who use their cell phones while driving. In a random sample of 250 California drivers 94 of these drivers stated that they used their cell phones while driving. Construct a 96% confidence interval for the true proportion of California drivers who use their cell phones while driving.
Choose one answer.

a. (0.3328, 0.4192)

b. (0.3248, 0.4272)

c. (0.3132, 0.4388)

d. None of the these are correct.



--
According to my calculations I get b. (0.3248, 0.4272), but I just wanted to make sure I was correct.

THanks
Plugging your numbers in my calculator i get (c)