Answer:
Step-by-step explanation:
Since the population standard deviation 
is unknown, and the sample standard deviation 
, must replace it, the 
distribution must be used for the confidence interval.
The sample size is n=8.
The degree of freedom is 
, 
.
With 95% confidence level, the 
(significance level) is 5%.
Hence with 7 degrees of freedom, 
. (Read from the t-distribution table see attachment)
The 95% confidence interval can be found by using the formula:
.
The sample mean is 
hours.
The sample sample standard deviation is 
hours.
We now substitute all these values into the formula to obtain:
.
We are 95% confident that the population mean is between 26.12 and 31.48 hours.
The answer is -21/8 or -2 5/8
Answer:
dy/dx = (cos y + y sin x) / (cos x + x sin y)
Step-by-step explanation:
y cos x = x cos y
y (-sin x) + dy/dx cos x = x (-sin y dy/dx) + cos y
-y sin x + dy/dx cos x = -x sin y dy/dx + cos y
dy/dx (cos x + x sin y) = cos y + y sin x
dy/dx = (cos y + y sin x) / (cos x + x sin y)
Answer:
the last one
Step-by-step explanation:
I checked
Given:
To find:
The simplified rational expression by subtraction.
Solution:
Let us factor 
. It can be written as 
.
using algebraic identity.
LCM of 
Make the denominators same using LCM.
Multiply and divide the first term by (x + 1) to make the denominator same.
Now, denominators are same, you can subtract the fractions.
Expand 
.
