Answer:
Recursive
a(1) = 9 ; a(n+1) = 3 * a(n)
Explicit
a(n) = 9 * 3^(n-1)
Answer:
Labrador retrievers
Step-by-step explanation:
We know that the mean
is:

and the standard deviation
is:

The probability that a randomly selected Labrador retriever weighs less than 65 pounds is:

We calculate the Z-score for X =65

So

Looking in the table for the standard normal distribution we have to:
.
Finally the amount N of Labrador retrievers that weigh less than 65 pounds is:


Labrador retrievers
No she can't spend $4.39 for each sandwich because if you divide 20 by 5 your quotient will be 4.
Answer:
90 days
Step-by-step explanation:
Let the rate per day for the 30 days period be x
Given that the rate drops to 1/3 of the rate used in 30 days period, it means that the new rate
= 1/3 x
If at a rate of x, the full tank runs for 30 days
at a rate of 1/3 x, the full tank would run for
= x/ (1/3 x) * 30 days
= 3 * 30 days
= 90 days
At the new rate, the full tank of oil will last for 90 days