Given:
The sample array is
x = [123.6 123.9 123.9 123.7 123.4 123.3 123.3 123.6 123.5 123.9 123.5 123.7 124.4 123.7 123.9 124.0 124.2 123.7 123.8 123.8 124.0 123.9 123.6 124.2 123.4 123.4 123.4 123.4 123.3 123.7
123.5 123.6 124.2 123.9 123.9 123.8 123.9 123.7 123.8 123.8]
From the calculator,
The sample size is
n = 40
The sample mean is
xavg = 123.73
The sample std. deviation is
s = 0.27
The expected population average is
μ = 120
Calculate the test statistic.
z = (xavg - μ)/(s/√n) .
= (123.73 - 120)/(0.27/√40)
= 87.36
The null hypothesis is
H₀: xavg = μ
and the alternate hypothesis is
xavg > μ
At α=0.01 level of significance, the one-tailed test has a rejection region of
α/2 = 0.005.
From standard tables, the test statistic clearly falls in the rejection region.
We should reject the null hypothesis and conclude that xavg > μ.
Answer:
The claim that the mean voltage is 120 V is false at the 0.01 significance level.
20 % = 20/100 = 1/5
1 red marble out of 5 total marbles
1 red marble and 4 not red marbles
odds in favor means number of favorable outcomes : number of unfavorable outcomes
this basically means red marbles : not red marbles
1: 4
Answer:
21/4
Step-by-step explanation:
1/2[-8 +16 - ( -2 1/2)] = 1/2 ( - 8 + 16 + 2 1/2) = 1/2 ( 8 + 2 1/2) = 1/2 * = 1/2 * 21/2 = 21/4
Answer:
4.5
Step-by-step explanation:
You can change 1/4 to a decimal and then multiply 2×2.25
Answer:
Step-by-step explanation:
What we want to fator is:
There is no common factor, but let's factor it by grouping. The first two addends can be factor as follows:
the second addends can be factor as well:
.
Then our original expression can be rewritten like
And here the is the common factor!
Finally, we can factor the quadratic expression as a difference of squares
Ant we get
now, we can extract the negative sign from , and we get
.