a reasearcher is wishing to estimate the proportion of x-ray machines that malfunction and produce excess radiation. a random sample of 40 machines is taken and 12 of the machines malfunction. find the 97% confidence interval for the proportion that malfunction in the population. a. (0.1428, 0.4572) b. (0.1808, 0.4192) c. (0.1134, 0.4866) d. (0.2491, 0.5009)

The law of large numbers states that as the number of observations drawn at random from a population with finite mean  increases, the mean  of the observed values:   a. tends to get closer and closer to the population mean .   b. gets smaller and smaller.   c. gets larger and larger.   d. fluctuates steadily between 1 standard deviation above and 1 standard deviation below the mean.   I collect a random sample of size n from a population and compute a 95% confidence interval for the proportion I observe from the population. What could I do to produce a new confidence interval with a larger width (larger margin of error) based on these same data?   a. I could use the same confidence level but compute the interval n times; approximately 5% of these intervals will be larger.   b. Nothing can guarantee absolutely that I will get a larger interval; I can only say the chance of obtaining a larger interval is 0.05.   c. I could use a smaller confidence…

Tina catches a 14-pound bass.  She does not know the population mean or standard deviation.  So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds.  Find the t and calculate a 95% (α = .05) confidence interval.

A sample of 80 University night school students' ages was obtained in order to estimate the mean age of all night school students. The sample mean was 25.1 years, with a sample variance of 16.2.     a. Give the point estimate for µ, the population mean, along with the margin of error.     b. Calculate the 99% confidence interval for µ.

In the country of United States of Heightlandia, the height measurements of ten-year-old children are approximately normally distributed with a mean of 53.3 inches, and standard deviation of 2.2 inches.What is the probability that the height of a randomly chosen child is between 51.3 and 57.1 inches? Do not round until you get your your final answer, and then round to 3 decimal places.Answer=___________ (Round your answer to 3 decimal places.)

Construct the confidence interval for the population mean μ. c=0.90​, x=16.7​, σ=7.0​, and n=45

tion. Use this information to construct the 90% and 95% confidence intervals fc of the confidence intervals. ce of a certain stock was $123.13. Assume the population standard deviation is

At a charter high school, the average GPA of a high school senior is known to be normally distributed. After a sample of 27 seniors is taken, the average GPA is found to be 2.85 and the sample variance is determined to be 0.16. Find a 95% confidence interval for the population mean GPA.   a. 2.5615 to 2.8585 b. 2.6358 to 3.0642 c. 2.6917 to 3.0083 d. 2.5167 to 2.9033