The bell curve attached below shows the normal distribution of the data.
We are looking the value of X such as the area to its left gives the probability of 0.75
We first need the z-score which we can obtain by reading from the z-table (as shown in the second picture below)
The z-score is = 0.7734
Then we use the following formula to work out X
z-score = (X - Mean) ÷ Standard Deviation
0.7734 = (X - 100) ÷ 15
0.7734×15 = X - 100
11.601 = X - 100
X = 11.601 + 100
X = 111.601 ≈ 112
Hence the third quartile is 112
Answer: 8.4 miles
Step-by-step explanation:
d = rt
Solve for her rate
21 = 5r
r = 21/5
r = 4.2
Solve for if the time is 2 hours and rate (solved previously) is 4.2
d = 4.2*2
d = 8.4
Answer:
There are 84 total boats.
Step-by-step explanation:
In order to find this, we first need to find the fraction which are red. We can do this by multiplying the whole by how many are not white.
1 * 1/4 = 1/4
Now we take that amount and multiply it by the amount that are not blue of the remaining.
1/4 * 3/7 = 3/28
Now that we have this, and we know this is 9 boats, we can divide 9 by this fraction and it will give us the total number of boats.
9 ÷ 3/28 = 84
I think the answer is a. -3x^2-x-5
-3^2= -(3)^2
The exponent of 2 only applies to the number 3. -(3)^2 should equal -9. This is true because according to the order of operations, exponents should be evaluated before multiplication. The negative sign here represents -1* 3^2.
If you want to find -3 to the power of 2 it must be written (-3)^2.