At a certain excavation site, archaeological studies have used the method of tree-ring dating in an effort to determine when people lived in there. Wood from several excavations gave a mean of (year) 1305 with a standard deviation of 22 years. The distribution of dates was more or less mound-shaped and symmetrical about the mean. Use the empirical rule to estimate a range of years centered about the mean in which about 68.3% of the data (tree-ring dates) will be found. Group of answer choices from 1239 to 1283 from 1305 to 1349 from 1239 to 1327 from 1327 to 1371 from 1283 to 1327

A researcher would like to estimate the mean amount of money that a family spends to within $75. If the amount spent by a family is considered to be normally distributed with a standard deviation of $412, what sample size would be necessary to be 93% confident?

An article in the San Jose Mercury News stated that students in the California state universitysystem take 4.25 years, on average, to finish their undergraduate degrees. Suppose you believe that the mean time is longer. You conduct a survey of 64 students and obtain a sample mean of 4.5 with a sample standard deviation of 1.5. Do the data support your claim at the 1% level?

Suppose that annual precipitation is normally distributed, with mean 50 inches, and standard deviation 12 inches. Find the 65th percentile of the precipitation distribution

On a measure of running speed on a 100 meter dash, students received timed scores ranging from 12 seconds to 24 seconds. The distribution of running times is normative with a mean of 16 seconds. Transferring this ratio data to standard scores for comparison with the results of classes from other departments, the mean score is assigned a standard score of 100 with a standard deviation of 10. From this example, a standard score of 99 would mean the actual value in seconds for an individual would be about a. 16 b. 12 c. 19 d. 24

During a quality assurance check, the actual contents (in grams) of six containers of protein powder were recorded as 1527, 1532, 1504, 1517, 1528, and 1516. (a) Find the mean and the median of the contents. (b) The third value was incorrectly measured and is actually 1520. Find the mean and the median of the contents again. (c) Which measure of central tendency, the mean or the median, was affected more by the data entry error? ..... (a) The mean is (Round to one decimal place as needed.) The median is (Type an integer or a decimal. Do not round.) (b) The mean is (Round to one decimal place as needed.) The median is (Type an integer or a decimal. Do not round.) (c) After correcting the error, the mean by and the median by The was affected more. (Round to one decimal place as needed.)

The distribution of the student heights at a large college is approximately bell shaped. If the mean height is 66 inches,and approximately 95% of the heights fall between 32 and 100 inches, then, the standard deviation of the heightdistribution is approximately equal to

Butt-to-knee length is approximately normally distributed with a mean of 23.1 inches and a standard deviation of 1.2.  Theater seats are designed to be comfortable for as many adults as possible.  If the seats are required to fit the middle 80% of the population, the seat must be comfortable for what butt-to-knee length range?

A sociologist found that in a sample of 45 retired men, the average number of jobs they had during theirlifetimes was 7.2. The population standard deviation is 2.3(a) Find the best point estimate of the mean.The best point estimate of the mean is

During a quality assurance check, the actual contents (in grams) of six containers of protein powder were recorded as 1524, 1526, 1499, 1512, 1532, and 1514. (a) Find the mean and the median of the contents. (b) The third value was incorrectly measured and is actually 1518. Find the mean and the median of the contents again. (c) Which measure of central tendency, the mean or the median, was affected more by the data entry error? (a) The mean is 1517.8. (Round to one decimal place as needed.) The median is 1519 (Type an integer or a decimal. Do not round.) (b) The mean is 1521 (Round to one decimal place as needed.) The median is 1521 (Type an integer or a decimal. Do not round.) (c) After correcting the error, the mean affected more. (Round to one decimal place as needed.) by and the median by The was