Exam 7: Estimating Parameters and Determining Sample Sizes

Use the confidence level and sample data to find a confidence interval for estimating the population µ. Round your answer to the same number of decimal places as the sample mean. -Test scores: $\mathrm { n } = 72 , \overline { \mathrm { x } } = 58.1 , \sigma = 6.2 ; 98 \%$ confidence

How do you determine whether to use the z or t distribution in computing the margin of error, $E = z \alpha / 2 \cdot \frac { \sigma } { \sqrt { n } } \text { or } E = t _ { \alpha / 2 } \cdot \frac { s } { \sqrt { n } } ?$

Express the confidence interval using the indicated format. -Express the confidence interval $0.039 < \mathrm { p } < 0.479$ in the form of $\hat { \mathrm { p } } \pm \mathrm { E }$ .

Assume that a sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. Round the margin of error to four decimal places. -99% confidence; n = 5900, x = 1770

Define in as clear language as possible how a 95% confidence interval can be used for hypothesis tests.

Solve the problem. Round the point estimate to the nearest thousandth. -32 randomly picked people were asked if they rented or owned their own home, 8 said they rented. Obtain a point estimate of the proportion of home owners.

Assume that a sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. Round the margin of error to four decimal places. -99% confidence; the sample size is 1110, of which 45% are successes

Of 380 randomly selected medical students, 21 said that they planned to work in a rural community. Find a 95% confidence interval for the true proportion of all medical students who plan to work in a rural community.

Find the critical value $\chi _ { \mathrm { R } } ^ { 2 }$ corresponding to a sample size of 19 and a confidence level of 99 percent.

Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p. -A survey of 300 union members in New York State reveals that 112 favor the Republican candidate for governor. Construct the 98% confidence interval for the true population proportion of all New York State union Members who favor the Republican candidate.