Answer:
The number of days are independent and the total number of minutes are dependent.
The required model for the situation is 
The table is shown below:
Step-by-step explanation:
Consider the provided information.
Joshua spends 25 minutes of each day reading. Let d be the number of days that he reads, and let m represent the total minutes of reading.
We need to determine which variable is independent and which is dependent.
Here, the number of days are independent and the total number of minutes are dependent.
If he spends 25 minutes each day. So the total number of minutes in d days are:

The required model for the situation is 
Now make the table which showing the number of minutes spent reading over 7 days.
Substitute the value of d from 1 to 7 in 
Number of days(D) Minutes(M)
1 25
2 50
3 75
4 100
5 125
6 150
7 175
The answer is $2267.25
30.23*75=2267.25
The grandfather would be your parents.Hope it helps :)
Correct answer is: P(x<6) is 0.123 and it is usual.
Solution:-
Given that the time a person takes to decide which shoes to purchase follows normal distribution. Which has mean = 8.21 minutes and standard deviation 1.90
Then probability of individual takes less than 6 minutes is
P(X<6) = 
= 
= 0.1230
Typically we say an event with a probability less than 5% is unusual.
But here P(X<6) = 0.123 is greater than 5% hence this is usual.