Answer: 42
explanation : 90-48=41
Answer:
Yes, we can conclude that the population standard deviation of TV watching times for teenagers is less than 2.66
Step-by-step explanation:
H0 : σ² = 2.66²
H1 : σ² < 2.66²
X²c = (n - 1)*s² ÷ σ²
sample size, n = 40
Sample standard deviation, s = 1.9
X²c = ((40 - 1) * 1.9²) ÷ 2.66²
X²c = 140.79 ÷ 7.0756
X²c = 19.897
Using a confidence level of 95%
Degree of freedom, df = n - 1 ; df = 40 - 1 = 39
The critical value using the chi distribution table is 25.6954
Comparing the test statistic with the critical value :
19.897 < 25.6954
Test statistic < Critical value ; Reject the Null
Hence, we can conclude that the population standard deviation of TV watching times for teenagers is less than 2.66
Answer:
f(x) = -5x - 4
Step-by-step explanation:
We want to get the inverse of the following function:
f^-1(x) = (-1/5)x - 4/5
To do that, we have to replace x with f(x) and f^-1(x) with x, as follows:
x = (-1/5)f(x) - 4/5
And then solve for f(x), the inverse of f^-1(x).
x + 4/5 = (-1/5)f(x)
f(x) = -5x + (-5)4/5
f(x) = -5x - 4
To check our result we compute a pair (x, f(x))
x f(x)
1 -5*1 - 4 = -9
which has to be equivalent to (-9, 1) in the original function
x f^-1(x)
-9 (-1/5)*(-9) - 4/5 = 1
Answer:
2
Step-by-step explanation:
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