Answer:
The answer is below
Step-by-step explanation:
1)
mean (μ) = 12, SD(σ) = 2.3, sample size (n) = 65
Given that the confidence level (c) = 90% = 0.9
α = 1 - c = 0.1
α/2 = 0.05
The z score of α/2 is the same as the z score of 0.45 (0.5 - 0.05) which is equal to 1.65
The margin of error (E) is given as:

The confidence interval = μ ± E = 12 ± 0.47 = (11.53, 12.47)
2)
mean (μ) = 23, SD(σ) = 12, sample size (n) = 45
Given that the confidence level (c) = 88% = 0.88
α = 1 - c = 0.12
α/2 = 0.06
The z score of α/2 is the same as the z score of 0.44 (0.5 - 0.06) which is equal to 1.56
The margin of error (E) is given as:

The confidence interval = μ ± E = 23 ± 2.8 = (22.2, 25.8)
Answer:
The number of people on the bus after the second stop is 8 less than the number of peoples on the bus before the 2:30 stop.
Step-by-step explanation:
Let
be the total number of peoples on the bus before 2:30 stop.
For the first stop at 2:30:
The bus let off 13 people, so, the total number of remaining people on the bus 
again, the bus let on 8 people, so, the total number of people on the bus


For the second stop after 10 minutes (i.e at 2:40):
The bus let off 3 people, so, the total number of remaining people on the bus 

After the second stop, the number of people on the bus is
, where P_0 number of peoples on the bus before 2:30 stop.
Hence, the number of people on the bus after the second stop is 8 less than the number of peoples on the bus before the 2:30 stop.
Answer:
In 4 Hours
Step-by-step explanation:
1 hour: A: 30.25 B: 34.25
2 hours: A: 35.5 B: 38.5
3 Hours: A: 40.75 B: 42.75
4 Hours: A: 46 B: 46