Over the past several months, an adult patient has been treated for tetany (severe muscle spasms). This condition is associated with an average total calcium level below 6 mg/dl. Recently, the patient's total calcium tests gave the following readings (in mg/dl). Assume that the population of x values has an approximately normal distribution. 9.9 8.4 10.5 8.9 9.4 9.8 10.0 9.9 11.2 12.1 (a) Use a calculator with mean and sample standard deviation keys to find the sample mean reading x and the sample standard deviation s. (Round your answers to two decimal places.) x =  mg/dl s =  mg/dl (b) Find a 99.9% confidence interval for the population mean of total calcium in this patient's blood. (Round your answer to two decimal places.) lower limit      mg/dl upper limit      mg/dl (c) Based on your results in part (b), do you think this patient still has a calcium deficiency? Explain.

Over the past several months, an adult patient has been treated for tetany (severe muscle spasms). This condition is associated with an average total calcium level below 6 mg/dl. Recently, the patient's total calcium tests gave the following readings (in mg/dl). Assume that the population of x values has an approximately normal distribution. 9.9 9.0 10.1 8.9 9.4 9.8 10.0 9.9 11.2 12.1 (a) Use a calculator with mean and sample standard deviation keys to find the sample mean reading and the sample standard deviation s. (in mg/dl; round your answers to two decimal places.) x = _______ mg/dls = _______ mg/dl (b) Find a 99.9% confidence interval for the population mean of total calcium in this patient's blood. (in mg/dl; round your answer to two decimal places.) lower limit  _______ mg/dlupper limit  _______mg/dl (c) Based on your results in part (b), do you think this patient still has a calcium deficiency? Explain. Yes. This confidence interval suggests that the patient may still…

In a particular statistics exam, the 35th percentile of final exam score is 42, and the 70th  percentile of final exam score is 76. A histogram of the scores approximately follows the normal curve. What is the approximate standard deviation of the final exam scores? Hints: What is the z value in the normal table that gives you closest to 35% of the area between -z and z? Now what does that tell you about the number of SDs in between 42 inches and 76 inches? You might find it helpful to draw a picture of the normal curve with original units and standard units. Group of answer choices a. 7.5 b. 13.1 c. 20.7 d. 37.8

In a particular statistics exam, the 10th percentile of final exam score is 59, and the 90th percentile of final exam score is 93. A histogram of the scores approximately follows the normal curve. What is the approximate standard deviation of the final exam scores? Hints: What is the z value in the normal table that gives you closest to 80% of the area between -z and z? Now what does that tell you about the number of SDs in between 59 inches and 93 inches? You might find it helpful to draw a picture of the normal curve with original units and standard units. 13.1 26.2 17.2 6.5

Find z such that 56% of the standard normal curve lies between −z and z. (Round your answer to two decimal places.

Over the past several months, an adult patient has been treated for tetany (severe muscle spasms). This condition is associated with an average total calcium level below 6 mg/dl. Recently, the patient's total calcium tests gave the following readings (in mg/dl). Assume that the population of x values has an approximately normal distribution. 10.1 8.8 10.3 8.5 9.4 9.8 10.0 9.9 11.2 12.1 (a)  Use a calculator with mean and sample standard deviation keys to find the sample mean reading  and the sample standard deviation s. (in mg/dl; round your answers to two decimal places.) =   mg/dls =   mg/dl (b)  Find a 99.9% confidence interval for the population mean of total calcium in this patient's blood. (in mg/dl; round your answer to two decimal places.)lower limit          mg/dlupper limit          mg/dl

A water footprint is a measure of the appropriation of fresh water. The per capita water footprint (in mega gallons) in a certain country for a recent year can be approximated by a normal distribution, as shown in the figure. (a) What water footprint represents the 86th percentile? (b) What water footprint represents the 28th percentile? (c) What water footprint represents the third quartile? u= 1.78 Mgal o = 2.76 Mgal E -6.22 1.78 9.78 Mega gallons (a) The water footprint that represents the 86th percentile is Mgal. (Round to two decimal places as needed.) (b) The water footprint that represents the 28th percentile is Mgal. (Round to two decimal places as needed.) (c) The water footprint that represents the third quartile is Mgal. (Round to two decimal places as needed.)

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 5.8 parts/million (ppm). A researcher believes that the current ozone level is at an excess level. The mean of 26 samples is 5.9 ppm with a standard deviation of 0.6. Does the data support the claim at the 0.01 level? Assume the population distribution is approximately normal. Step 1 of 5: State the null and alternative hypotheses. Answer Ho: Ha: Tables Keypad Keyboard Shortcuts

The target population is the weekly income of students in 2017. The mean weekly income of STAT150 students in 2017 (population mean), µ, was $198 and the population standard deviation, o, was $34. A histogram of the weekly income of a large number of students from this population is shown, below, to illustrate the shape of the weekly income distribution. Frequency 70 60 50 40 30 20 10 0 140 160 Histogram of Weekly Income 180 220 Weekly Income 200 240 260 280 a) What shape is the distribution of student weekly income?