A voluntary response sample is always valid.
Answer: 
Step-by-step explanation:
Since, the total number of contestant = 7,
Thus, the probability that out of 3 contestant, me and my friend is chosen
= 
= 
= 
= 
⇒ Third Option is correct.
Answer:
34
Step-by-step explanation:
42/21 = x/17
solve to get the answer
2 = x/17
2*17 = x/17 * 17
34 = x
Answer:
No
Step-by-step explanation:
49 ≥ 10d
49 ≥ 10(8)
49 ≥ 80
49 has to be greater than or equal to 80
d = 8 isn’t a solution
Answer: (0.5496, 0.5754)
Step-by-step explanation:
The confidence interval for population proportion (p) is given by :-
, where
= Sample proportion , n= sample size , z*= Critical z-value.
Let p be the proportion of all college students who are in favor of banning Hawaiian shirt.
Given, A random sample of 4000 college students yielded 2250 who are in favor of banning Hawaiian shirts.
i.e. n=4000

z-value for 90% confidence level is 1.645
Now , 90% confidence interval for p would be :


Hence, the required 90% interval = (0.5496, 0.5754)