Answer:
20,820
Step-by-step explanation:
Let
denote the number of minutes spent brushing his teeth, and let
be the mean and
the standard deviation for this distribution.
The z-score corresponding to this probability is approximately
, which means
Next, (note the sign change)
The corresponding z-score is approximately
, so you have
Solving the two equations for
and
, you'll find that the mean is approximately
and the standard deviation is approximately
.
Answer:
a)False: In a sample of 100 men who are heavy smokers, exactly 24 of them will contract lung cancer.
b)True: In a sample of 100 men who are heavy smokers, the number who will contract lung cancer is likely to be close to 24.
c)True: As more and more heavy-smoking men are sampled, the proportion who contract lung cancer will approach 0.24. Circle one: TRUE FALSE
3/4 + 2/3 = 17/12
7/8 - 2/3 = 5/24
3/5 x 1/3 = 1/5
4/7 x 2/3 = 8/21