Find the critical value za

Find the critical value za/2 that corresponds to the given confidence level, Statistics help
Subject
Mathematics

Question Description
1. Find the critical value za/2 that corresponds to the given confidence level.

2. Express the confidence interval 0.222

3. A research institute poll asked respondents if they acted to annoy a bad driver. In the poll n=2503 and x=1177 who said that they honked. Find the best point estimate of the population proportion p?

4. Use the given data to find the minimum sample size required to estimate a population proportion or percentage. Margin of error:0.08 confidence level 90% p and q unknown. n=?

5. A student wants to estimate the mean score of all college students for a particular exam. First use the range rule of thumb to make a rough estimate of the standard deviation of those scores. Possible scores range from 100 to 1800. Use technology and the estimated standard deviation to determine the sample size corresponding to a 99% confidence level and a margin of error of 100 points. What isn't quite right with this exercise? The range rule of thumb estimate for the standard deviation is?

6. Express the confidence interval (0.034,0.122) in the form of p-E

7. A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 620 babies were born, and 341 of them were girls. Use the sample data to construct a 99% confidence interval estimate of the percentage of girls born. Based on theresult, does the method appear to be effective? _

8. An online site presented thisquestion, "Would the recent norovirus outbreak deter you from taking a cruise?" Among the 34,575 people who responded 62% answered "yes." Use the sample data to construct a 90% confidence interval estimate for the proportion of the population of all people who would respond "yes" to that question. Does the confidence interval provide a good estimate of the population proportion? _