Answer:
1 minute
Step-by-step explanation:
We can see that Lisa types 165 words in 3 mins.
So she types 55 words in 1 minute.
How did I work that out?
Well, all you really do is 
which is equal to 
if you divide top and bottom by 3. Anything divided by 1 is itself.
Answer:
C
Step-by-step explanation:
Answer: Option (c) is correct.
68% of the data points lie between 10 and 18.
Step-by-step explanation: Given : a normal distribution with a standard deviation of 4 and a mean of 14
We have to choose the sentence that correctly describes a data set that follows a normal distribution with a standard deviation of 4 and a mean of 14.
Since, given 68% data.
We know mean of data lies in middle.
And standard deviation is distribute equally about the mean that is 50% of values less than the mean and 50% greater than the mean.
So, 68% of data lies
mean - standard deviation = 14 - 4 = 10
mean + standard deviation = 14 + 4 = 18
So, 68% of the data points lie between 10 and 18.
Answer:
y = 2cos5x-9/5sin5x
Step-by-step explanation:
Given the solution to the differential equation y'' + 25y = 0 to be
y = c1 cos(5x) + c2 sin(5x). In order to find the solution to the differential equation given the boundary conditions y(0) = 1, y'(π) = 9, we need to first get the constant c1 and c2 and substitute the values back into the original solution.
According to the boundary condition y(0) = 2, it means when x = 0, y = 2
On substituting;
2 = c1cos(5(0)) + c2sin(5(0))
2 = c1cos0+c2sin0
2 = c1 + 0
c1 = 2
Substituting the other boundary condition y'(π) = 9, to do that we need to first get the first differential of y(x) i.e y'(x). Given
y(x) = c1cos5x + c2sin5x
y'(x) = -5c1sin5x + 5c2cos5x
If y'(π) = 9, this means when x = π, y'(x) = 9
On substituting;
9 = -5c1sin5π + 5c2cos5π
9 = -5c1(0) + 5c2(-1)
9 = 0-5c2
-5c2 = 9
c2 = -9/5
Substituting c1 = 2 and c2 = -9/5 into the solution to the general differential equation
y = c1 cos(5x) + c2 sin(5x) will give
y = 2cos5x-9/5sin5x
The final expression gives the required solution to the differential equation.
Answer:
5. f(x) = 10,000 (1.5)^x
Step-by-step explanation:
We would have to multiply the original amount by 1.50^x because the initial amount would be 1, and 50% increase would be .5 so 1.5 and you raise it to the number of years to show the total increase.
Let's test it.
Initial:
10,000
After 1 year
10,000 + (.5*10000)
10,000 + 5000 = 15,000
After 2 years
15,000 + (.5*15000)
15,000 + 7500 = 22,500
Let's try our equation.
f(x) = 10,000 (1.5)^x
x = 2
10,000(1.5)^2
10,000(2.25) = 22,500
The same!
