Answer:
(53.812 ; 58.188) ; 156
Step-by-step explanation:
Given that :
Sample size (n) = 51
Mean (m) = 56
Standard deviation (σ) = 9.5
α = 90%
Using the relation :
Confidence interval = mean ± Error
Error = Zcritical * (standard deviation / sqrt (n))
Zcritical at 90% = 1.645
Error = 1.645 * (9.5 / sqrt(51))
Error = 1.645 * 1.3302660
Error = 2.1882877
Hence,
Confidence interval :
Lower boundary = 56 - 2.1882877 = 53.8117123
Upper boundary = 56 + 2.1882877 = 58.1882877
Confidence interval = (53.812 ; 58.188)
2.)
Margin of Error (ME) = 1.25
α = 90%
Sample size = ((Zcritical * σ) / ME)^2
Zcritical at 90% = 1.645
Sample size = ((1.645 * 9.5) / 1.25)^2
Sample size = (15.6275 / 1.25)^2
Sample size = 12.502^2 = 156.3000
Sample size = 156
Answer:
71.1
Step-by-step explanation:
Answer:
9,8,1,0,-10,-15
Step-by-step explanation:
HOPEE HELPSS HEHE
4x=-3y+17 becomes 4x+3y=17
4x+3y=17
3x-4y=-6
alrighty
elimination
muliply first equation by 4 and 2nd by 3 and add them
16x+12y=68
9x-12y=-18
add them
25x+0y=50
25x=50
idivide both sides by 25
x=2
sub back
3x-4y=-6
3(2)-4y=-6
6-4y=-6
-4y=-12
y=3
(x,y)
(2,3)
