Question

1. Use the given degree of confidence and sample data to construct a confidence interval for the point) population proportion p. A survey of 865 voters in one state reveals that 408 favor approval of an issue before the legislature. Construct the 95% confidence interval for the true proportion of all voters in the state who favor approval. 0 0.438<p0.505 0 0.444 p0.500 0 0.435<p<0.508 O 0.471 p0.472 2. Use the given data to find the minimum sample size required to estimate the populatiorn (i point) proportion. Margin of error: 0.09; confidence level 90%; from a prior study, p is estimated by 0.23. 060 O 53 180 0 5 3. Find the indicated critical z value. point) Find the critical value ze2 that corresponds to a 98% confidence level. 2.575 2.05 2.33 1.75 4. Use the given degree of confidence and sample data to construct a confidence interval for the s paint population proportion p. Of 140 adults selected randomly from one town, 35 of them smoke. Construct a S38 confidence interval for the true percentage of all adults in the town that smoke 15.654 K p < 34,4 25.0% < p < 31.0%

Answer 1

1) Sample proportion is

The confidence interval is given by

For 95% confidence interval

So,

20-2 = (1.96)V/0 472(1-0.172) ~ 0.033 865

Hence the interval is

Option 1st is correct

2) The margin of error is given by

Using the given values we get

So sample size required is 60

Option first is correct

3) The critical value for 98% confidence is 2.33

Option 3rd is correct