I Believe its 2/5
(just know im not too sure)
Answer:
A. 2/5, 0.40, 40%
Step-by-step explanation:
To turn a fractions into a decimal divided the numerator by the denominator. 2/5=0.40.
4 and 8::::::: because they have no variable u can add 4 and 8 which would be 12
Answer:
(a) (6, 2)
Step-by-step explanation:
The system of equations has one of them in y= form, so it lends itself to solution by substitution.
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Using the equation for y to substitute into the first equation, we have ...
2x -y = 10
2x -(-1/2x +5) = 10 . . . . . substitute for y
2x +1/2x -5 = 10 . . . . . eliminate parentheses
5/2x = 15 . . . . . . . . . add 5, collect terms
x = 6 . . . . . . . . . . . multiply by 2/5
Using the equation for y, we have ...
y = -1/2(6) +5 = -3 +5
y = 2
The solution is (x, y) = (6, 2).
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)
