Question

A national survey interviewed 3800 people ages 18 and older nationwide by telephone. One question asked was the amount of gasoline they used in the previous week. Of those sampled, the average response was 11.75 gallons. A parameter in this situation is _____.

Answer 1

For this case a parameter represent the population data and for this case the parameter would be the true mean
`\mu` who represent the amount of gasoline they used in the previous week

`\bar X= (\sum_(i=1)^n X_i)/(3800) =11.75`

And the sample mean is an unbiased estimator of the true mean.

Explanation:

For this case a parameter represent the population data and for this case the parameter would be the true mean
`\mu` who represent the amount of gasoline they used in the previous week

And in order to estimate the parameter of interest we use a survey of n =3800 and the sample mean who represent an statistic is given by:

`\bar X = (\sum_(i=1)^n X_i)/(n)`

And we got:

`\bar X= (\sum_(i=1)^n X_i)/(3800) =11.75`

And the sample mean is an unbiased estimator of the true mean.