Answer:
(a) 
(b) 4 miles
Step-by-step explanation:
Given:
The sequence of run is an arithmetic sequence.
Miles traveled on day 1 = 1 mile
Miles traveled on day 7 = 2 miles
(a).
Explicit formula for an arithmetic sequence is given as:

Here, 
So,

Therefore, the explicit definition of the above sequence is given as:

Where,
is the miles covered on
day.
(b)
In order to find the distance covered by her on day 19, we plug in 19 for n in the above formula. This gives,

Therefore, the number of miles covered by her on day 19 is 4 miles.
Answer: 8359
Step-by-step explanation:
The formula for sample size needed for interval estimate of population proportion :-

Given : The significance level : 
Critical value : 
Previous estimate of proportion : 
Margin of error : 
Now, the required sample size will be :-

Hence, the required sample size = 8359
y+2 = 3x
subtract 2 from each side
y = 3x-2
Answer:
3:7
Step-by-step explanation:
18/6(largest factor)=3
42/6(largest factor)=7