Answer:
99% confidence interval for the population average examination score is between a lower limit of 69.2872 and an upper limit of 82.7128.
Step-by-step explanation:
Confidence interval = mean +/- margin of error (E)
mean = 76
variance = 144
sd = sqrt(variance) = sqrt(144) = 12
n = 25
degree of freedom (df) = n - 1 = 25 - 1 = 24
confidence level (C) = 99% = 0.99
significance level = 1 - C = 1 - 0.99 = 0.01 = 1%
t-value corresponding to 24 df and 1% significance level is 2.797
E = t×sd/√n = 2.797×12/√25 = 6.7128
Lower limit = mean - E = 76 - 6.7128 = 69.2872
Upper limit = mean + E = 76 + 6.7128 = 82.7128
99% confidence interval is (69.2872, 82.7128)
Answer:
a) ⅖+⅓ = 6/15 + 5/15 = 11/15
b) 5/9 - 1/2 = 10/18 - 9/18 = 1/18
Answer: x = 6/4
Step-by-step explanation:
4x + 2 = 8
4x = 6
x = 6/4 or 1 1/2
Hope this helped :)
Slope =1.000/2.000=0.5
X-intercept=10/-1=-10.0
Y-intercept=10/2=5
(x-3)^2 + (x+5)^2=9^2
(x^2-6x+9) + (x^2+10x+25)=81
2x^2+4x+34=81
2x^2+4x-47=0
From here just use quadratic formula
