A farmer wants to test the effectiveness of a pest control method in allowing strawberry blooms to yield marketable strawberries. Of a random sample of 100 blooms,77 yield marketable strawberries. Is this evidence that two-thirds or more of all blooms grown with this pest control method ends up as marketable strawberries? The 95% large-sample confidence interval for the proportion of blooms that yield marketable strawberries is?

A study of 420,007 cell phone users found that 136 of them developed cancer of the brain or nervous system. Prior to this study of cell phone​ use, the rate of such cancer was found to be 0.0319​% for those not using cell phones. Complete parts​ (a) and​ (b). Use the sample data to construct a 90​% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system. b. Do cell phone users appear to have a rate of cancer of the brain or nervous system that is different from the rate of such cancer among those not using cell​ phones? Why or why​ not?

A high school is running a campaign against the over-use of technology in teens. The committee running the campaign decides to look at the difference in social media usage between teens and adults. They take a random sample of 200 teens in their city (Group 1) and find that 85% of them use social media, and then take another random sample of 180 adults in their city (Group 2) and find that 55% of them use social media. Find a 90% confidence interval for the difference in proportions. Enter the confidence interval

Research published in the Journal of Quantitative Criminology(Mar. 2010) revealed that the risk of burglaries in homes located on cul-de-sacs is lower than from homes on major roads. What size sample would be required to estimate the proportionof cul-de-sac homes in your home city that were burglarized in the past year within3% at the 95% confidence level?

study of 420,077 cell phone users found that 133 of them developed cancer of the brain or nervous system. Prior to this study of cell phone​ use, the rate of such cancer was found to be 0.0236​% for those not using cell phones. Complete parts​ (a) and​ (b). a. Use the sample data to construct a 90​% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system.

A study of 420,048 cell phone users found that 137 of them developed cancer of the brain or nervous system. Prior to this study of cell phone​ use, the rate of such cancer was found to be 0.0256​% for those not using cell phones. Complete parts​ (a) and​ (b).       a. Use the sample data to construct a 90​% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system.   enter your response here​%<p<enter your response here​% ​(Round to three decimal places as​ needed.) b. Do cell phone users appear to have a rate of cancer of the brain or nervous system that is different from the rate of such cancer among those not using cell​ phones? Why or why​ not?     A. No​, because 0.0256​% is included in the confidence interval.   B. Yes​, because 0.0256​% is included in the confidence interval.   C. Yes​, because 0.0256​% is not included in the confidence interval.   D. No​, because 0.0256​% is not…

In a study designed to assess the side effects of two drugs, 50 animals were given drug A,  and 50 animals were given Drug B. Of the 50 receiving Drug A, 11 showed undesirable side effects, while 8 of those receiving Drug B reacted similarly. Find the 98% confidence interval for the true difference in population proportions, pˆ A − pˆ B.

In an engineering class, students want to determine the difference in the mean strength between two different types of building materials—Type A, which is relatively inexpensive, and Type B, which is slightly more expensive. The students take a random sample of 60 of the Type A building material and a random sample of 27 of the Type B building material. Given the mean strength for each sample, the students construct a 95% confidence interval for the difference in population means.   (a) Determine the degrees of freedom for the conservative approach for finding the t critical value.   (b) Find the t critical value associated with 95% confidence. (Use a table or SALT. Round your answer to two decimal places.)

In a study of treatments for very painful​ "cluster" headaches,... Find the 90% confidence interval using technology.

Fewer young people are driving. In year A, 65.9% of people under 20 years old who were eligible had a driver's license. Twenty years later in year B that percentage had dropped to 45.7%. Suppose these results are based on a random sample of 1,600 people under 20 years old who were eligible to have a driver's license in year A and again in year B. (a) At 95% confidence, what is the margin of error of the number of eligible people under 20 years old who had adriver's license in year A? (Round your answer to four decimal places.)  ______________ At 95% confidence, what is the interval estimate of the number of eligible people under 20 years old who had a driver's license in year A? (Round your answers to four decimal places.) ______________________ to ________________________ (b) At 95% confidence, what is the margin of error of the number of eligible people under 20 years old who had a driver's license in year B? (Round your answer to four decimal places.) At 95% confidence, what is…