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:
10/4
Step-by-step explanation:
Randomthing2143 is right
Answer:
The measurement of angle B is 135°
The measurement of angle A is 60°
The measurement of angle C is 75°
Step-by-step explanation:
Angle A is the same value of 60, Angle B is pretty much just 180 - 45, and so is angle C.
3 = 3/4(b - 8)
Switch sides
3/4(b - 8) = 3
Next, multiply both sides by 4
4 * 3/4(b - 8) = 3 * 4
Then simplify,
3(b - 8) = 12
Next, divide both sides by 3
3(b - 8)/3 = 12/3
Then, simplify
b - 8 = 4
Then, add 8 to both sides
b - 8 + 8 = 4 + 8
Simplify, b = 12
