Answer:
The standard deviation of this probability distribution is 1.2.
Step-by-step explanation:
We have that:
P(X = 0) = 0.25
P(X = 1) = 0.3
P(X = 2) = 0.1
P(X = 3) = 0.35
Mean:
Each value multiplied by its probability. So
Variance:
Sum of the squares of the values subtracted from the mean, and multiplied by its probability.

Standard deviation:
Square root of the variance. So

The standard deviation of this probability distribution is 1.2.
Answer:
The <em>p</em>-value is 0.809.
Step-by-step explanation:
In this case we need to perform a significance test for the standard deviation.
The hypothesis is defined as follows:
<em>H</em>₀: <em>σ</em>₀ = 4 vs. <em>Hₐ</em>: <em>σ</em>₀ ≤ 4
The information provided is:
<em>n</em> = 9
<em>s</em> = 3
Compute the Chi-square test statistic as follows:


The test statistic value is 4.5.
The degrees of freedom is:
df = n - 1
= 9 - 1
= 8
Compute the <em>p</em>-value as follows:

*Use a Chi-square table.
Thus, the <em>p</em>-value is 0.809.
Sin(A) = opposite/hypotenuse = 12/13
Cos(A) = adjacent/hypotenuse = 5/13
Tan(A) = opposite/adjacent = 12/5