Suppose the mean height of women age 20 years or older in a certain country is 62.7 inches. One hundred randomly selected women in a certain city had a mean height of 63.9 inches. At the 1% significance level, do the data provide sufficient evidence to conclude that the mean height of women in the city differs from the national mean? Assume that the population standard deviation of the heights of women in the city is 3.8 inches. Click here to view a partial table of areas under the standard normal curve. Set up the hypotheses for the one-mean z-test. Ho H 62.7 H3 u 62.7 The test statistic is z= 3.16 (Round to two decimal places as needed.) The P-value is (Round to four decimal places as needed.)

Suppose that the quarterly sales levels among healthcare information systems companies are approximately normally distributed with a mean of 12 million dollars and a standard deviation of 1.1 million dollars. One health care information systems company considers a quarter a "failure" if its sales level that quarter is in the bottom 15% of all quarterly sales levels. Determine the sales level (in millions of dollars) that is the cutoff between quarters that are considered "failures" by that company and quarters that are not. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place.

Suppose that the heights of 4-year old boys are normally distributed with a mean of 103cm and a standard deviation of 4.05. What height represents the 95th percentile?

A Statistics instructor wanted to compare the scores on the same final exam given to students at a local community college and local university.  The Statistics instructor feels that students at the community college would be better prepared and have higher exam scores on the final exam. After grading the final exams from both institutions, the Statistics instructor found that for a sample of 36 community college students, the sample had a mean score of 84 with a standard deviation of 3.4.  A sample of 45 university students had a mean score 79 with a standard deviation of 2.6.  Construct a 95% confidence interval for the difference between population mean exam scores. Round your final results to one decimal place.      _____________     ≤      ???  −  ?????      ≤     ______________

It has been found that with the standard dosage of a drug, the change in people’s uric acid levelis normally distributed with a mean of 240 and a standard deviation of 60. What proportionof people receiving the standard dosage of this drug experience changes in uric acid levelbetween 210 and 270?

Describe  the scores in a sample  that has a standard  deviation of zero

A study by the National Center for Health Statistics suggested that women between the ages 20 and 29 in the US have a mean BMI of 26.8 with a standard deviation of 7.4. A BMI of 30 or greater is considered as being obese. What proportion of women in this age range are obese?

Suppose that the quarterly sales levels among health care information systems companies are approximately normally distributed with a mean of 12 million dollars and a standard deviation of 1.3 million dollars. One health care information systems company considers a quarter a "failure" if its sales level that quarter is in the bottom 20% of all quarterly sales levels. Determine the sales level (in millions of dollars) that is the cutoff between quarters that are considered "failures" by that company and quarters that are not. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place. million dollars X S

The U.S. Center for Disease Control reports that in year 1900, the mean life expectancy is 47.6 years for whites and 33 years for nonwhites. (Click here for reference data) Suppose a survey of randomly selected death records for white and nonwhite people born in 1900 from a certain county is conducted. Of the 110 whites surveyed, the mean life span was 48.2 years with a standard deviation of 11.2 years and of the 95 nonwhites, the mean life span was 39.3 years with a standard deviation of 16 years. Conduct a hypothesis test at the 0.05 level of significance to determine whether there was no difference in mean life spans in the county for whites and nonwhites in year 1900. Preliminary: Is it safe to assume thatnw≤5% of all white people born in 1900 andnnw≤5% of all nonwhite people born in 1900? No Yes Is nw≥30 and nnw≥30 ? No Yes   Test the claim: Determine the null and alternative hypotheses. H0: μw      μnw Ha: μw      μnw  Determine the test statistic. Round to four…

According to a recent report the battery life for a new line of laptop computers has a mean of 9 hours with a standard deviation of 2.4 hours.  If battery life is normally distributed what percentage of new laptops will last between 8 and 11 hours on a single charge?