Questions from Essentials of Statistics

Q: x1 = 10, n1 = 20, x2 = 18,

x1 = 10, n1 = 20, x2 = 18, n2 = 30; left-tailed test, α = 0.10; 80% confidence interval We have provided the numbers of successes and the sample sizes for independent simple random samples from two po...

Q: x1 = 18, n1 = 40, x2 = 30,

x1 = 18, n1 = 40, x2 = 30, n2 = 40; left-tailed test, α = 0.10; 80% confidence interval We have provided the numbers of successes and the sample sizes for independent simple random samples from two po...

Q: x1 = 14, n1 = 20, x2 = 8,

x1 = 14, n1 = 20, x2 = 8, n2 = 20; right-tailed test, α = 0.05; 90% confidence interval We have provided the numbers of successes and the sample sizes for independent simple random samples from two po...

Q: x1 = 15, n1 = 20, x2 = 18,

x1 = 15, n1 = 20, x2 = 18, n2 = 30; right-tailed test, α = 0.05; 90% confidence interval We have provided the numbers of successes and the sample sizes for independent simple random samples from two p...

Q: x1 = 18, n1 = 30, x2 = 10,

x1 = 18, n1 = 30, x2 = 10, n2 = 20; two-tailed test, α = 0.05; 95% confidence interval We have provided the numbers of successes and the sample sizes for independent simple random samples from two pop...

Q: x1 = 30, n1 = 80, x2 = 15,

x1 = 30, n1 = 80, x2 = 15, n2 = 20; two-tailed test, α = 0.05; 95% confidence interval We have provided the numbers of successes and the sample sizes for independent simple random samples from two pop...

Q: In the 1940s and early 1950s, the public was greatly concerned

In the 1940s and early 1950s, the public was greatly concerned about polio. In an attempt to prevent this disease, Jonas Salk of the University of Pittsburgh developed a polio vaccine. In a test of th...

Q: In an article titled “Great White, Deep Trouble” (

In an article titled “Great White, Deep Trouble” (National Geographic, Vol. 197(4), pp. 2–29), Peter Benchley—the author of JAWS—discussed various aspects of the Great White Shark (Carcharodon carchar...

Q: In the United States, approximately 450,000 vasectomies are performed

In the United States, approximately 450,000 vasectomies are performed each year. In this surgical procedure for contraception, the tube carrying sperm from the testicles is cut and tied. Several studi...

Q: For several years, evidence had been mounting that folic acid reduces

For several years, evidence had been mounting that folic acid reduces major birth defects. A. Czeizel and I. Dudas of the National Institute of Hygiene in Budapest directed a study that provided the s...