Answer:
D.) The expected value is 1.78
Step-by-step explanation:
The expected value of a probability distribution is evaluated using the formula.
Expected Value,
Therefore, from the given probability distribution, we have:
E(X)=(0*0.3)+(1*0.2)+(2*0.16)+(3*0.2)+(4*0.04)+(5*0.1)
E(X)=1.78
The Expected value of X is 1.78.
The correct option is D.
Let p be the population proportion of parents who had children in grades K-12 were satisfied with the quality of education the students receive.
Given : Several years ago, 39% of parents who had children in grades K-12 were satisfied with the quality of education the students receive.
Set hypothesis to test :
Sample size : n= 1055
Sample proportion :
Critical value for 95% confidence :
Confidence interval :
Since , Confidence interval does not contain 0.39.
It means we reject the null hypothesis.
We conclude that 95% confidence interval represents evidence that parents' attitudes toward the quality of education have changed.