Answer:
(48.106 ; 53.494)
Step-by-step explanation:
Given the data:
X : 52 48 49 52 53
Sample mean = ΣX / n
n = 5
Sample mean, xbar = 254 / 5 = 50.8
Standard deviation, s = 2.17 (using calculator)
The standard error (SE) : s/√n =2.17/√5 = 0.970
The degree of freedom, df = n-1
df = 5 - 1 = 4
Tscore(0.05, 4) = 2.776
Confidence interval :
Xbar ± Tscore*standard error
50.8 ± (2.776 * 0.970)
50.8 ± 2.694
Lower boundary = 50.8 - 2.694 = 48.106
Upper boundary = 50.8 + 2.694 = 53.494
(48.106 ; 53.494)
32% of 300 is 96. 100% of 300 is 32 percent of 300 equals 96 so it is 300
Answer:
see below
Step-by-step explanation:
8(n + 2)(n + 4) = 1,144
FOIL
8(n^2 +2n+4n+8) = 1144
Divide each side by 8
8/8(n^2 +2n+4n+8) = 1144/8
(n^2 +2n+4n+8) = 143
Combine like terms
n^2 +6n+8 = 143
Subtract 143 from each side
n^2 +6n+8 -143= 0
Combine like terms
n^2 +6n -135 =0
Factor
What two terms multiply to -135 and add to 6
-9*15 =-135
-9+15 = 6
(n-9) (n+15) =0
Using the zero product property
n-9 =0 n+15=0
n = 9 n=-15
The length cannot be negative so n = -15 cannot be a solution
n =9
Answer: Use a bar or a number line. Try my example with -6.
Step-by-step explanation: Example: x + 2 > 12
Subtract 2 from both sides:
x + 2 − 2 > 12 − 2
Simplify:
x > 10
Solved^
Answer:
Step-by-step explanation:
2 cos x + √ 2 = 0
2 cos x = -√ 2
cos x = -√ 2 / 2
x = arcCos( -√ 2 / 2 )
so to solve we have to use "co-terminal " angles .. do you know what I'm saying? do you understand the words coming out of my mouth :DDDDD OKay back to math and not movie lines .. :P
x = arcCos( √ 2 / 2 )
x = 45 °
now find the "co terminal" angle that is on 45 ° but in the correct quadrant... since the -√ 2 is negative.. we now that we go down the y axis.. but also positive on the x axis.. soooo.. that put the angle in the 4th quadrant... so this is an angle of 315° if we go in the CCW ( counter clock wise ) direction but it's also -45° in the CW (clock wise ) direction
below is the table to remember the trig special angles
notice how it's 1,2,3,4 .. so it's super easy to remember.. the trig books don't show you this "trick" :P
copy and paste this to your computer some where handy
Sin(0) = 0/2 =0
Sin(30)= /2 = 1/2
Sing(45) =/2 =/2
Sin(60)=/2 = /2
Sin(90)=/2 = 1
Cos is exactly the same but counts backwards from 90°
Cos(90) = 0/2 = 0
Cos(60) = /2 = 1/2
Cos(45) = /2 =/2
Cos(30) = /2 =/2
Cos(0) = /2 = 1