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In a random sample of 50 dog owners enrolled in obedience training, it was determined that the mean amount of money spent per owner was $109.33 per class and the standard deviation of the amount spent per owner is $28.17, construct and interpret a 99% confidence interval for the mean amount spent per owner for an obedience class.

Assume that the weight loss for the first month of a diet program varies between 5 pounds and 50 pounds, and is spread evenly over the range of possibilities, so that there is a uniform distribution.  What is the probability of the weight loss more than 35 pounds?

In a simple random sample of 300 employed people, 78 said that they bring work home with them at least occasionally. a) Construct and interpret a 96% confidence interval for the proportion of all employed people who bring work home with them at least occasionally. b) Find the minimum sample size would be needed for a 99% confidence interval with the margin of error of 0.025.

A final exam for Math 50 has a mean of 76.9 with standard deviation of 7.7.  If 49 students are randomly selected, a) describe the sampling distribution of the sample mean. b) find the probability that the mean of the 49 students test scores is at least 80.

With individual lines at it various windows, a movie theater manager finds that the standard deviation for normally distributed waiting times for customers on Friday evening is 8.3 minutes.  The movie theater manager experiments with a single, main waiting line and finds that for a random sample of 20 customers, the waiting times for customers have a mean of 15 minutes and a standard deviation of 4.9 minutes.  Does this suggest that a single line has lower variation among waiting times (shorter waiting times) for customers at 1% significance level? [Make sure to provide the null and alternative hypotheses, check the requirement to provide the appropriate test statistic, p-value or critical value, decision, and conclusion.]  

A survey of 1000 college seniors working towards an undergraduate degree was conducted. Each student was asked, “Are you planning or not planning to pursue a graduate degree?” Of the 1000 surveyed, 652 stated that they were planning to pursue a graduate degree. a) Construct and interpret a 98% confidence interval for the proportion of college seniors who are planning to pursue a graduate degree. b) Find the minimum sample size would be needed for a 95% confidence interval with the margin of error of 0.025.

A recent study claimed that less than 15% of middle school students are overweight.  In a random sample of 160 middle school students, 18 were found to be overweight.  At

In the previous year the proportion of deposits in checking accounts at a certain bank that were made electronically was 35%. The bank wishes to determine if the proportion is higher this year. It examined 1200 deposit records and found that 456 were electronic. Determine, at the 5% level of significance, whether the data provide sufficient evidence to conclude that more than 35% of all deposits to checking accounts are now being made electronically. [Make sure to provide the null and alternative hypotheses, check requirements to provide the appropriate test statistic, p-value or critical value, decision, and conclusion.]

Find the area under the standard normal curve to the right of  z = – 1.87.

Light wave of wavelength enters a glass of refraction index . What is the wavelength inside the glass?