Answer:
0.101
Step-by-step explanation:
Given that :
Standard deviation, s = 0.2
Sample variance, s² = 0.0653
Sample size, n = 10
Population variance = σ² = 0.04
We use the Chi square distribution :
(n - 1)s² / σ²
For P(s² ≥ 0.065)
(n - 1)s² / σ² = (10 - 1)*0.0653 / 0.04
(n - 1)s² / σ² = 0.585 / 0.04 = 14.625
P(s² ≥ 14.625) = 0.101 ( chi squee calculator).
Answer:
Step-by-step explanation:
(12+10+x)/3=15
15*3=12+10+x
45-12-20=x
X=23
Let's call x1: The rate per hour of the number one mechanic. X2: The rate per hour of mechanic number two. The first thing you should do is identify the system of equations that best describes the problem. In this case it is a system of 2 equations with two unknowns which when solved gives a total of x1 = 85 $ / h and x2 = 50 $ / h. Attached solution.
Answer:
A. 
B. 
Step-by-step explanation:
A. 
Where,


Plug in the values to get a polynomial that represents the area of the tool




B. To find area, when x = 4.5 in, plug in the value of x into the equation for the area of the tool.





Answer:
As the sample size increases, the variability decreases.
Step-by-step explanation:
Variability is the measure of actual entries from mean. The less the deviations the less would be the variance.
For a sample of size n, we have by central limit theorem the mean of sample follows a normal distribution for random samples of large size.
X bar will have std deviation as 
where s is the square root of variance of sample
Thus we find the variability denoted by std deviation is inversely proportion of square root of sample size.
Hence as sample size increases, std error decreases.
As the sample size increases, the variability decreases.