The mean annual income of certified welders is normally distributed with a mean of $50,000 and a population standard deviation of $2,000. The shipbuilding association wishes to find out whether their welders earn more or less than $50,000 annually. The alternate hypothesis is that the mean is not $50,000. If the level of significance is 0.10, what is the decision rule?

The empirical rule estabilishes the percentages that are 1,2, and 3 deviations from the mean True Flase

Solar energy is considered by many to be the energy of the future. A recent survey was taken to compare the cost of solar energy to the cost of gas or electric energy. Results of the survey revealed that the distribution of the amount of the monthly utility bill of a three-bedroom house using gas or electric energy had a mean of $117 and a standard deviation of $13. If the distribution can be considered normal: Approximately what percentage of homes will have a monthly utility bill less than $78? Note: Do NOT include the "%" sign Do NOT round any decimals, if applicable

As reported in Runner's World magazine, the times of the finishers in the New York City 10- km run are normally distributed with mean 61 minutes and standard deviation 9 minutes. The 75th percentile for the finishing times is 67 minutes. What is the interpretation of this value?

It is known that incomes from the USA follow a normal distribution with a mean of $55,000 and a standard deviation of $12,000.  A researcher took a sample of 100 people in the USA and obtained a sample mean of $67,000 with a standard deviation of $18,000.  What are the characteristics of the sampling distribution. A. Mean = $55,000 and Standard Deviation of the Mean = $1200 B. Mean = $55,000 and Standard Deviation of the Mean = $12000 C. Mean = $67,000 and Standard Deviation of the Mean = $569.21 D. Mean = $67,000 and Standard Deviation of the Mean = $1800

Is a measure of 29 inches "far away" from a mean of 19 inches? Suppose the data come from a sample whose standard deviation is 2 inches. A. How many standard deviation is 29 inches from 19 inches? b. Is 29 inches far away from a mean of 19 inches? c. Suppose the standard deviation of the underlying data is 7 inches. Is 29 inches far away from a mean of 19 inches?

The college physical education department offered an advanced first aid course last summer. The scores on the comprehensive final exam were normally distributed, and the z-scores for some of the students are shown below. Robert 1.05 Juan 1.51 Haley −1.95 Joel 0.00 Jan −0.67 Linda 1.57 (a) If the mean score was ? = 151 with standard deviation ? = 16, what was the final exam score for each student?

In nutrition, the recommended daily allowance of vitamins is a number set by the government to guide an individual's daily vitamin intake. Actually, vitamin needs vary drastically from person to person, but the needs are closely approximated by a normal curve. To calculate the recommended daily allowance, the government first finds the standard deviation and the average need for vitamins among people in the population. The recommended daily allowance is then defined as the mean plus 2.7 times the standard deviation. What fraction of the population will receive adequate amounts of vitamins under this plan? Click here to see page 1 of the table for areas under the standard normal curve. Click here to see page 2 of the table for areas under the standard normal curve. The fraction of the population that will receive adequate amounts of vitamins under the given plan is (Type an integer or decimal rounded to the nearest thousandth as needed.)

ryan has collected data on individual income (reported in dollars) and has not found any outliers. ryan wants to calculate the average income in his data. which measure of central tendency should he use? -mean -variance -mode -median

Suppose there is a city where the mean cost per month of a one-bedroom apartment is $1,500, with a standard deviation of $250. Approximately what percentage of one-bedroom apartments in the city cost between $750 and $1,000?