Calcium is an essential nutrient for strong bones and for controlling blood pressure and heart beat. Because most of the body's calcium is stored in bones and teeth, the body withdraws the calcium it needs from the bones. Over time, if more calcium is taken out of the bones than is put in, the result may be thin, weak bones. This is especially important for women who are often recommended a calcium supplement. A consumer group activist assumes that calcium content in two popular supplements are normally distributed with the same unknown population variance, and uses the following information obtained under independent sampling: Supplement 1 Supplement 2 x1 = 1,049 mg x2 = 1,053 mg s1 = 16 mg s2 = 11 mg ni = 13 n2 = 16 Let uj and u2 denote the corresponding population means. Construct a 95% confidence interval for the difference u1 - u2. (Round the interval to two decimal places.)

Calcium is an essential nutrient for strong bones and for controlling blood pressure and heart beat. Because most of the body's calcium is stored in bones and teeth, the body withdraws the calcium it needs from the bones. Over time, if more calcium is taken out of the bones than is put in, the result may be thin, weak bones. This is especially important for women who are often recommended a calcium supplement. A consumer group activist assumes that calcium content in two popular supplements are normally distributed with the same unknown population variance, and uses the following information obtained under independent sampling: Supplement 1 Supplement 2 x1 = 1,049 mg x2 = 1,053 mg s1 = 16 mg s2 = 11 mg ni = 13 n2 = 16 Let uj and u2 denote the corresponding population means. Construct a 95% confidence interval for the difference u1 - u2. (Round the interval to two decimal places.)

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Researchers want to examine the following traits of a new medication: the half-life of the medication in the body, effectiveness of the medication in treating symptoms, and the rate of insomnia in users of the medication. Which of the variables require using a placebo during the tests? Select all that apply. A : Half-life of the medication in the body because knowing they are taking the medication will affect how fast a patient metabolizes the medication. B : Effectiveness of the medication in treating symptoms because knowing they are taking the medication will affect how patients report the effectiveness. C : Rate of insomnia in users of the medication because knowing they are taking the medication will affect how patients report insomnia.
Caffeine is a stimulant found in coffee, tea, soft drinks and other drinks and foods. After consumption, caffeine is absorbed into the blood stream and carried throughout the body and to the brain. In moderate amounts (~300 mg per day) it causes increased attentiveness, it reduces feelings of fatigue, and it enables most people to think clearly and concentrate for longer periods. Caffeine also increases heart rate and rate of respiration. In large quantities (>600 mg per day) its effects are magnified. People sometimes feel irritable, distracted and tense. People often use caffeine to increase mental alertness. Some people are more sensitive than others to the effects of caffeine. People who consume caffeine regularly may build up a tolerance to its effects. Further, since caffeine is mildly addictive, people who regularly consume caffeine may experience some withdrawal effects if they stop consumption. The Study In this study, three people each consumed varying levels of…
Your cognitive capacity is significantly reduced when your smartphone is within reach, even if it’s off. A professor conducted experiments with nearly 600 smartphone users in an attempt to measure how well people can complete tasks when they have their smartphones nearby even when they’re not using them. In one experiment, the researchers asked study participants to sit at a computer and perform a task that required full concentration in order to succeed. The tests were geared to measure participants’ available cognitive capacity – that is, the brain’s ability to hold and process data at any given time. Before beginning, participants were randomly instructed to place their smartphones either on the desk face down (group 1; 200 participants), in their pockets (group 2; 200 participants), or in another room (group 3; 200 participants). All participants were instructed to turn their phones to silent. The researchers found that participants with their phones in another room significantly…
The last answer I got is wrong. Please help.
There have been many studies recently concerning coffee drinking and cholesterol level. While it is known that several coffee-bean components can elevate blood cholesterol level, it is thought that a new type of paper coffee filter may reduce the presence of some of these components in coffee. The effect of the new filter on cholesterol level will be studied over a 10-week period using 300 nonsmokers who each drink 4 cups of caffeinated coffee per day. Each of these 300 participants will be assigned to one of two groups: the experimental group, who will only drink coffee that has been made with the new filter, or the control group, who will only drink coffee that has been made with the standard filter. Each participant’s cholesterol level will be measured at the beginning and at the end of the study. Describe an appropriate method for assigning the subjects to the two groups so that each group will have an equal number of subjects. In this study, the researchers chose to include a…
Annabel, a retail analyst, has been following Under Armour, Incorporated, the pioneer in the compression-gear market. Compression garments are meant to keep moisture away from a wearer's body during athletic activities in warm and cool weather. Annabel believes that the Under Armour brand attracts a younger customer relative to other companies. The accompanying file includes data on the age of the customers and whether or not they purchased Under Armour (Purchase; 1 for purchase. 0 otherwise). Click here for the Excel Data File *-1. Use the appropriate statistical software to estimate a logistic regression model using Under Armour as the response variable and age as the predictor variable. Note: Negative values should be indicated by a minus sign. Round your answers to 2 decimal places. Intercept Age Coefficient a-2. Compute the predicted probability of an Under Armour purchase for a 20-year-old customer and a 30-year-old customer. Note: Round coefficient estimates to at least 4…
A team of government researchers would like to determine whether a new tax on cigarettes has any effect on people’s smoking behavior. Specifically, they are expecting that by increasing the price of cigarettes, people’s will buy fewer packs of cigarettes (ultimately leading to decreases in cigarette smoking). During the year before the tax was imposed, stores located in rest areas on the state highways reported selling an average of µ = 410 packs per day. The distribution of daily sales was approximately normal. For a random sample of n = 25 days during the first year following the new tax, the researchers found an average of x̅= 380 packs per day for the same stores, with a standard deviation of s = 60. Is the sample mean sufficient to conclude that there was a significant decrease in cigarette purchases after the new tax? Use a one-tailed test with α = .01.
In North America, between 100 million and 1 billion birds die each year by crashing into windows on buildings, more than any other human-related cause. This figure represents up to 5% of all birds in the area. One possible solution is to construct windows angled downward slightly, so that they reflect the ground rather than an image of the sky to a flying bird. An experiment by Klem et al. (2004) compared the number of birds that died as a result of vertical windows, windows angled 20 degrees off vertical, and windows angled 40 degrees off vertical. The angles were randomly assigned with equal probability to six windows and changed daily; assume for this exercise that windows and window locations were identical in every respect except angle. Over the course of the experiment, 30 birds were killed by windows in the vertical orientation, 15 were killed by windows set at 20 degrees off vertical, and 8 were killed by windows set at 40 degrees off vertical. . Clearly state an appropriate…
Emily is trying to check if the nutritional content of different formulas have different effects on mice. She uses five mice to test each type of formulas (A, B, and C) and Formula A is simply a placebo. Each mouse's weight is recorded in grams. At the end of a specified time period, each mouse is weighed again and the net gain in grams is recorded as shown in Table 1 below. Formula Formula Formula A В 40 47 51 32 38 41 42 49 38 36 46 46 39 44 49 Using an F-test, determine whether or not the variance in weight gain is statistically the same among the mice that were using Formula B and Formula C. Test at a confidence level of 90%. (HINT: Remember that the bigger standard deviation goes in the numerator when calculating the test statistic) a. Should we run the test on all three columns or only on two columns? (Write "2" or "3" in the blank): b. The F-test statistic calculated for this problem is (Round to three decimal places). c. The critical-F value for this problem is (Round to three…
A patient consults a doctor to check up his ill health. Doctor examines him and advises him that he is having deficiency of two vitamins, vitamin A and vitamin D. Doctor advises him to consume vitamin A and D regularly for a period of time so that he can regain his health. Doctor prescribes tonic X and tonic Y, which are having vitamin A, and D in certain proportion. Also advises the patient to consume at least 40 units of vitamin A and 50 units of vitamin Daily. The cost of tonics X and Y and the proportion of vitamin A and D that present in X and Y are given in the table below. Formulate the model to minimize the cost of tonics.
Is Your Nose Getting Bigger?Next time you see an elderly man, check out his nose and ears! While most parts of the human body stop growing as we reach adulthood, studies show that noses and ears continue to grow larger throughout our lifetime. In one study1 examining noses, researchers report "Age significantly influenced all analyzed measurements:" including volume, surface area, height, and width of noses. In a test to see whether males, on average, have bigger noses than females, the study indicates that "p<0.01."Let group 1 be males and group 2 be females.1Sforza C, Grandi G, De Menezes M, Tartaglia GM, Ferrario VF, "Age- and sex-related changes in the normal human external nose", Forensic Science International, 2011 Jan 30;204(1-3):205.e1-9. (a) State the hypotheses. Your answer should be an expression composed of symbols: =,≠,<,>,μ,μ1,μ2,p,p1,p2,ρ,p^,p^1,p^2,r. H0: vs Ha:Edit
Early life corresponds to the first bacterial colonization of the digestive tract, creating a microbiome thought to play an important role in human development. What might be the effect of early exposure to antibiotics on children's development? One study followed 11,532 full-term babies all born in the county of Avon, United Kingdom, during 1991 and 1992. Exposures to antibiotics during infancy were recorded, along with measures of body mass at regular intervals over several years. The researchers found that antibiotic exposure during the first six months of life was associated with increased body mass later in childhood.