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:
y - 1 = -4(x - 4)
Step-by-step explanation:
The point-slope form looks like y-k = m(x-h), where (h,k) is a point on the line and m is the slope.
Here, y - 1 = -4(x - 4). This is in point-slope form.
Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
Answer:
79.25
Step-by-step explanation:
