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:415
Step-by-step explanation:
Angle DBE + Angle CBE = 90°
(0.1x-22)° + (0.3x-54)° = 90°
(0.4x - 76)° = 90°
(0.4x)° = 166°
x= 1660/4 = 415
(0.1 415 - 22)° + (0.3 415-54)° = 90°
41.5 - 22 + 124.5 - 54 = 90
166 - 76 = 90
Answer:
c. dividing is the inverse of multiplying because it doesn't really relate the equation like the others do.
There are 6.4 Kilometers in 4 miles