The equation is
. We can rewrite the equation as:
.
Our next step here is to take the square root of both sides, remembering that
.
Thus, we have
. Our final step is solving the absolute value equation, which yields:
or
.
Solution set: {
}
Answer: 
Step-by-step explanation:
Given : Sample size : n= 9
Degree of freedom = df =n-1 =8
Sample mean : 
sample standard deviation : 
Significance level ; 
Since population standard deviation is not given , so we use t- test.
Using t-distribution table , we have
Critical value = 
Confidence interval for the population mean :
90% confidence interval for the mean value will be :
Hence, the 90% confidence interval for the mean value=
Answer:
Annie's height= 49 cm
Her brother's height= b+ 49
Let the sum be represented as x
x- 49 = b
Answer:
Step-by-step explanation:
1. Shifting 
right or left, top or down, as the graph in the question has the same illustration of . Consider
2. find a and b by using two sample points from the graph: 
and 
