I have 25 statistic questions need to be answered the numbers not in order

16. How hot is the air in the top (crown) of a hot air balloon? Information from Ballooning: The Complete Guide to Riding the Winds, by Wirth and Young (Random House), claims that the air in the crown should be an average of 100°C for a balloon to be in a state of equilibrium. However, the temperature does not need to be exactly 100°C. What is a reasonable and safe range of temperatures? This range may vary with the size and (decorative) shape of the balloon. All balloons have a temperature gauge in the crown. Suppose that 57 readings (for a balloon in equilibrium) gave a mean temperature of x = 97°C. For this balloon, σ ≈ 15°C.

(a) Compute a 90% confidence interval for the average temperature at which this balloon will be in a steady-state equilibrium. (Use 1 decimal place.)

17. Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther. A small group of 16 of Allen's hummingbirds has been under study in Arizona. The average weight for these birds is x = 3.15 grams. Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with σ = 0.40 gram.

(a) Find an 90% confidence interval for the average weights of Allen's hummingbirds in the study region. What is the margin of error? (Use 2 decimal places.)

Find the sample size necessary for an 90% confidence level with a maximal error of estimate E = 0.06 for the mean weights of the hummingbirds. 

18. Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma. Over a period of months, an adult male patient has taken nine blood tests for uric acid. The mean concentration was x = 5.35 mg/dl. The distribution of uric acid in healthy adult males can be assumed to be normal, with σ = 1.89 mg/dl.

(a) Find a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. What is the margin of error? (use 2 decimal places)

 Given σ = 1.89. Find the necessary sample size for a 95% confidence level with E = 1.10 for the mean concentration of uric acid in this patient's blood. 

19. What price do farmers get for their watermelon crops? In the third week of July, a random sample of 38 farming regions gave a sample mean of x = $6.88 per 100 pounds of watermelon. Assume that σ is known to be $1.86 per 100 pounds.

Find a 99% confidence interval for the population mean price (per 100 pounds) that farmers in this region get for their watermelon crop. What is the margin of error? Use 2 decimal places.

20. At Burnt Mesa Pueblo, the method of tree ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution.

(a) Perform a descriptive statistic calculation to find the sample mean and standard deviation (to the nearest year).

(b) Find a 99% confidence interval for the mean of all tree ring dates from this archaeological site. (Round to nearest integer.)

21. How much do wild mountain lions weigh? Adult wild mountain lions (18 months or older) captured and released for the first time in the San Andres Mountains gave the following weights (pounds). Assume that the population of x values has an approximately normal distribution.

(a) Find the sample mean and standard deviation. (Enter your answers to one decimal place)

(b) Find a 99% confidence interval for the population average weight μ of all adult mountain lions in the specified region. (Enter your answers to one decimal place.)

22. Owning a candy store:
With some interest in running your own business and a decent credit rating, you can probably get a bank loan on startup costs for a candy store franchise. Startup costs (in thousands of dollars) for a random sample of candy stores are given below. Assume that the population of x values has an approximately normal distribution.

(a) Find the sample mean and standard deviation (in thousands of dollars). Use 1 decimal place.

(b) Find a 99% confidence interval for the population average startup costs μ for candy store franchises. Use 1 decimal place.

23. What percentage of hospitals provide at least some charity care? Based on a random sample of hospital reports from eastern states, the following information was obtained (units in percentage of hospitals providing at least some charity care). Assume that the population of x values has an approximately normal distribution.

(a) Find the sample mean and standard deviation (to 1 decimal place).

(b) Find a 99% confidence interval for the population average μ of the percentage of hospitals providing at least some charity care. (Use 1 decimal place.)

24. Given a normal distribution with σ = 0.360. Find the required sample size for a 80% confidence level (estimating the mean) with a 0.12 margin-of-error. 

25. Given a normal distribution with σ = 1.910. Find the required sample size for a 95% confidence level (estimating the mean) with a 1.04 margin-of-error. 

26. Given the sample results taken from a normal population distribution: mean = 4.65, σ = 0.32, and n = 10. 
Find the margin-of-error and the 99% confidence interval for the population mean. (use 2 decimal places) 

27. Given the sample results taken from a normal population distribution: mean = 7.25, σ = 1.77, and n = 7. 
Find the margin-of-error and the 90% confidence interval for the population mean. (use 2 decimal places) 

28. Given the following data that was sampled from a normal population distribution:

Determine a 99% confidence interval for the population mean. (round to nearest integer)

29. Given the following data that was sampled from a normal population distribution:

Determine a 99% confidence interval for the population mean. (use 1 decimal place)

More down

30. Use the following table to find tc for a 0.99 confidence level when the sample is 7. (Use 3 decimal places.)

31. Use the following table to find tc for a 0.90 confidence level when the sample is 3. (Use 3 decimal places.)