Answer:
s = - 1 ± 
Step-by-step explanation:
Given
s² + 2s - 6 = 0 ( add 6 to both sides )
s² + 2s = 6
To complete the square
add ( half the coefficient of the s- term )² to both sides
s² + 2(1)s + 1 = 6 + 1
(s + 1)² = 7 ( take the square root of both sides )
s + 1 = ±
( subtract 1 from both sides )
s = - 1 ± 
Thus
s = - 1 -
, s = - 1 + 
Answer:
the answer is -33 srry couldn't explain :(
3*60 = 180 minutes
80/180 = 0.44
1-0.44 = 0.56
it was a 56% decrease in commute time
Solution :
Given :
Sample mean, 
Sample size, n = 129
Sample standard deviation, s = 8.2
a. Since the population standard deviation is unknown, therefore, we use the t-distribution.
b. Now for 95% confidence level,
α = 0.05, α/2 = 0.025
From the t tables, T.INV.2T(α, degree of freedom), we find the t value as
t =T.INV.2T(0.05, 128) = 2.34
Taking the positive value of t, we get
Confidence interval is ,


(32.52, 35.8)
95% confidence interval is (32.52, 35.8)
So with
confidence of the population of the mean number of the pounds per person per week is between 32.52 pounds and 35.8 pounds.
c. About
of confidence intervals which contains the true population of mean number of the pounds of the trash that is generated per person per week and about
that doe not contain the true population of mean number of the pounds of trashes generated by per person per week.
He had saved 320 initially
Step-by-step explanation:
Let the amount he saved be 'a'
Amount spent = 20 + 40 + 30
= 90
His grand father gave 50
At the end he has 280
280 = a - 90 +50
a = 280 -50 +90
= 320
He had saved 320 initially