Answer:
179
Step-by-step explanation:
The total number of animals in the river was 632.
A herd of 187 elephants and 266 zebras left the river area.
Adding them up, the total number of animals that left the river area is:
187 + 266 = 453
Therefore, the total number of animals left at the river area is the subtraction for the animals that left the river area from the number of animals that were there initially:
632 - 453 = 179
Answer:
PART C OF WHAT I CAN HELP IF YOU TELL ME
Answer:
3
Step-by-step explanation:
Let x = # of boxes of felt-tip pens.
(x)(3.44)+(4x)(4.41) = 63.24
21.08x = 63.24
x = 3
Because x = 3, the man bought 3 boxes of felt-tip pens and 12 boxes of ballpoint pens.
They will require between 18.42 and 31.58 minutes.
We want the middle 90%. The two probability values associated with this would be 0.95 and 0.05; this would leave 5% below and 5% above, giving us the middle 90%.
Using a z-table (http://www.z-table.com) we see that the z-score associated with an area to the left of 0.05 is between -1.64 and -1.65; since it is equally distant from both we will use -1.645.
The z-score associated with an area of the left of 0.95 is between 1.64 and 1.65; since it is equally distant from both we will use 1.645.
The formula for a z-score is
z = (X-μ)/σ
-1.645 = (X-25)/4
Multiplying by 4 on both sides,
-1.645(4) = X-25
-6.58 = X-25
Adding 25 to both sides,
-6.58+25 = X
18.42 = X
For the upper bound,
1.645 = (X-25)/4
Multiplying both sides by 4,
1.645(4) = X-25
6.58 = X-25
Adding 25 to both sides,
6.58+25 = X
31.58 = X
The times are between 18.42 and 31.58 minutes.
