Answer:
estimate a population proportion
Step-by-step explanation:
The choices are missing in the question, correct question is:
In a January 2017 Washington Post-ABC News poll, respondents were asked “There is a proposal to offer nearly 140 billion dollars in tax cuts for private companies if they pay to build new roads, bridges and transportation projects. The companies then could charge tolls for people to use these roads, bridges and transportation. Do you support or oppose this proposal?” Of the 1005 people polled, 66 percent of those surveyed said they oppose the above proposal. An objective of this study is to ________ .
a. test a claim about a population mean
b. estimate a population mean
c. test a claim about a population proportion
d. estimate a population proportion
Population proportion estimate will give the percentage of people who <em>support or oppose</em> the proposal of 140 billion dollars in tax cuts for private companies so that they build charge tolled new roads, bridges and transportation projects.
People are asked "Do you support or oppose this proposal?", this shows that the purpose of the study is to estimate a <em>population proportion</em>.
Answer:
it's the last one on the bottom (the one you chose)
Step-by-step explanation:
No of outcomes =16
favourable outcome=4
<span>probability of getting exactly 3 heads=0.25</span>
Mean:
E[Y] = E[3X₁ + X₂]
E[Y] = 3 E[X₁] + E[X₂]
E[Y] = 3µ + µ
E[Y] = 4µ
Variance:
Var[Y] = Var[3X₁ + X₂]
Var[Y] = 3² Var[X₁] + 2 Covar[X₁, X₂] + 1² Var[X₂]
(the covariance is 0 since X₁ and X₂ are independent)
Var[Y] = 9 Var[X₁] + Var[X₂]
Var[Y] = 9σ² + σ²
Var[Y] = 10σ²
