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=
The negative solution is x = –1.
Solution:
Let the number be x.
Square of a number = x²
3 times a number = 3x
Difference of square of a number and 4 = 3 times that number
Subtract 3x from both sides of the equation, we get
–3x can be written as x – 4x.
1st bracket have common term x and bracket have –4 common term.
Take common term x + 1 outside.
<em>By zero factor principle, if AB = 0 then A = 0 or B = 0.</em>
x + 1 = 0, x – 4 = 0
x = –1, x = 4
The negative solution is x = –1.