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= 
Acute angle between 0 and 90 degrees I think
Answer:
<u>The altitude or height of the triangle is 6 meters.</u>
Step-by-step explanation:
1. Let's review the information provided to us to answer the question correctly:
Area of a triangle = 60 m²
Base = 20 m
2. What is the altitude (h) of the triangle?
Let's recall that the formula of the area of a triangle is:
Area = (Base * Height)/2
Replacing with the real values, we have:
60 = (20 * Height)/2
60 * 2 = (20 * Height) (Multiplying by 2 at both sides)
120 = 20 Height
Height = 120/20 = 6 meters
<u>The altitude or height of the triangle is 6 meters.</u>
Answer:
option D
Step-by-step explanation:
take 39 degree as reference angle
using cos rule
cos 39 = adjacent / hypotenuse
0.77 = x / 7
x = 7*0.77
x = 5.39
x = 5.4
Answer:
Step-by-step explanation:
First substitue the coordinates to the equation so
x=9, y=2
you would get
2=-3/7(9) + b
we put b because we are trying to find the new slope
multiply the two numbers above
2=-3/6/7 + b
subtract the whole number from both sides
b= 5/6/7
in equation would be
y= -3/7 + 5/6/7
Let me know if there is an error.