1. 15 Km
2. 17
3. 585.2
4. 243 dollars
Answer:
a) 5.6 years
b) 0.4478
Step-by-step explanation:
We are given the following in the question:
Mean, μ = 5.6 years
Standard Deviation, σ = 1.9 years
Sample size, n = 18
We are given that the distribution of amounts of time is a bell shaped distribution that is a normal distribution.
a) Mean of each sample.
The best estimator of the sample mean is the population mean itself. Thus, we have:

Thus, the sample mean is 5.6 years.
b) Standard error
Formula:

Putting values, we have.

Thus, the standard error is 0.4478.
Answer: 128
The log is base 4. To undo the log, we raise both sides as exponents and the base will be 4.
So log(4,y) = 1 turns into y = 4^1 and it becomes y = 4
Replace y with log(4,2x) and we end up with log(4,2x) = 4
Repeat the step of raising both sides as exponents to get 2x = 4^4 leading to 2x = 256
The last step is to divide both sides by 2, which is why the answer is x = 128.
Divide given eq. by -2, we get, x^2-4x+0.5=0. Here a=1, b=-4 and c=0.5. As disccriminant is given by sqrt(b^2-4*a*c).so sqrt((-4)^2-4*1*0.5)=3.7417.
Real roots are x1,2=-b+-discriminant
x1=-4+3.7417=-0.2583 and x2=-4-3.7417=-7.7417