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 118 whites surveyed, the mean life span was 46 years with a standard deviation of 11.8 years and of the 95 nonwhites, the mean life span was 37.9 years with a standard deviation of 14 years. Conduct a hypothesis test at the 0.01 level of significance to determine whether there was no difference in mean life spans in the county for whites and nonwhites in year 1900.

Q: A pharmaceutical company claims that a drug is effective in treating 90% of people having severe…

A: Given that,The random variable follows binomial distribution,n=6p=90%=0.9,q=1-p, q= 0.1

Q: A significant number of students completed a Statistics exam, and the final marks had a mean of 70…

A: Answer - A significant number of students completed a Statistics exam, and the final marks had a…

Q: Find the number of boys and the combined standard deviation

A: Given :  Our aim is to find the number of boys and combined standard deviation.

Q: According to the data from the National Health Survey, the height of all adult American women are…

A: The score is calculated below:

Q: In 1955, Life Magazine reported that the 27 year-old mother of three worked, on average, an 75 hour…

A: Given Information :  In 1955, Life Magazine reported that the 27 year-old mother of three worked, on…

Q: Assume that the mathematics score on the SAT are normally distributed with a mean of 500 and a…

A: Given

Q: In 1955, Life Magazine reported that a 25-year-old mother of three worked, on average, an 80 hour…

A: From the provided information, Sample size (n) = 71 Sample mean (x̅) = 83 Sample standard deviation…

Q: The National Center for Health Statistics reports that the average systolic blood pressure for males…

A: Here, The claim to be tested is "The medical director of a large company believes the average…

Q: If the number of degrees of freedom for a chi-square distribution is 21, what is the population mean…

A: Given: Degree of freedom = 21

Q: The heights of adult men in America are normally distributed, with a mean of 69.5 inches and a…

A: 69.5 2.62 64.4 2.53 American woman:

Q: If the height of 1000 students in a University Campus closely follows a normal distribution with a…

A:

Q: If the average number of textbooks in professors' offices is 14, the standard deviation is 5, and…

A: Given that For textbooks, mean = 14, and SD = 5 For age, mean = 42, and SD = 10

Q: If the mean height of bonsai trees is 52 cm with a standard deviation of 10 cm, 95% of the trees are…

A: NOTE : As per our guidelines we have to answer the first question if multiple questions are posted…

Q: Is it worth pursuing a doctoral degree in education if you already have an undergraduate degree? One…

A: Let Population 1 be the salaries for people with doctoral degrees and Population 2 be the salaries…

Q: In 1955, Life Magazine reported that the 25 year-old mother of three worked, on average, an 80hour…

A: Solution: Given information: n= 85 Sample size  x= 83.5 Sample mean μ= 80 Populaion Mean s= 10…

Q: What is the sum of the deviation scores for the data in the frequency distribution table below?

A: Sum of deviation  of scores from mean is always zero.

Q: If the standard deviation of sample A  is 5 and the standard deviation of sample B  is 12, what is…

A:

Q: The Virginia Cooperative Extension reports that the mean weight of yearling Angus steers is 1152…

A: Here mean = 1152 and SD = 84. z=(x-mean)/SD = (x-1152)/84

Q: According to the Runzheimer International, a typical business traveler spends an average of $281 per…

A: Here, µ = $281, σ = 47, and n = 65.

Q: A study of the Physics and Astronomy department has found that 95% of the graduate students drink…

A: Explanation:Here given the two means and find out the standard deviation of the sample follows the…

Q: According to the records of an electric company serving the Boston area, the mean electricity…

A: GivenMean(μ)=1650standard deviation(σ)=320

Q: If a data set has a mean of 80 and a standard deviation of 10, calculate + 1.5 standard deviations

A: Here, the data set has a mean of 80 and a standard deviation of 10.

Q: Suppose the exam average in a class is 48% with a standard deviation of 15. What proportion of…

A:

Q: Suppose a random sample of 25 measurements was taken from a population with a mean of 74 and a…

A: We know that,  Sample size (n) = 25 and population mean (μ) = 74 and population standard deviation…

Q: The head of maintenance at XYZ Rent-A-Car believes that the mean number of miles between services is…

A: Solution: Let X be the number of miles between services. From the given information, X has mean…

Q: reported that the 27-year-old mother of three worked, on average, a 75 hour week. Recently, many…

A: As the population standard deviation is not known, we will use a t-test. The null and alternative…

Q: If research samples 28 college students and wants to compare the sample mean of 8 to the population…

A: From the provided information, Sample size (n) = 28 Sample mean (x̄) = 8 Population mean (µ) = 12…

Q: in a group of 230 tests, how many students score within one standard deviation of the mean?

A: The probability that the students score within one standard deviation of the mean will be:…

Q: In an all boys school, the heights of the student body are normally distributed with a mean of 69…

A:

Q: If the standard error,  of a sample data set is 5 and the standard deviation,  of the distribution…

A: For a population with mean µ  and standard deviation σ, the standard error is σx̅ = σ/√n, where x̅…

Q: The heights of 18 year old men are normally distributed with a mean of 67 inches and a standard…

A: Given information- Population mean, µ = 67 inches Population standard deviation, σ = 3 inches We…

Q: The National Health Statistics Reports dated Oct. 22, 2008, stated that for a sample size of 277…

A:

Q: A recent study found that 69% of all adults over 50 wear sunglasses for driving. In a random sample…

A: Formula : Mean = np Standard Deviation  :

Q: The mean height of a population of men is 70.8 inches and the standard deviation is 3.2 inches. What…

A:

Q: It has been found that with the standard dosage of a drug, the change in people’s uric acid levelis…

A: Given X is normal Distributed with mean µ = 240.0 and standard deviation σ = 60.0 now will using…

Q: suppose the heights of 18-year-old men are approximately normally distributed, with mean 73 inches…

A:

Q: The heights of adult men in America are normally distributed, with a mean of 69.1 inches and a…

A: Heights of adult men is Normally Distributed with mean 69.1 inches and standard deviation 2.68…

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

A: If the standard deviation is zero there will be no dispersion of scores from the Mean. It means that…

Q: according to police sources, a car with a certain protection system will be recovered 90% of the…

A: Given problem is a binomial distribution with:

Q: If the mean is two, and the standard deviation is one, would a value of five be considered…

A: Unusual values : Unusual values should be lie outside the 2 standard deviation from the mean.   i.e.…

Q: As reported in Runner's World magazine, the times of the finishers in the New York City 10- km run…

A: Percentile : Percentile is the number such that certain percentage of the fall below that values.…

Q: The standard deviation of the distribution of sample means would be equal to:

A: The standard deviation of the distribution of sample means would be equal to ?

Q: In a survey of women in Canada, the mean height was 65 inches with a standard deviation of 3 inches.…

A:

Q: In an all boys school, the heights of the student body are normally distributed with a mean of 71…

A:

Q: If a normally distributed group of test scores have a mean of 70 and a standard deviation of 12,…

A: It is given that the mean is 70 and the standard deviation is 12.

Q: In 1955, Life Magazine reported that the 27 year-old mother of three worked, on average, an 75 hour…

A:

Q: In 1955, Life Magazine reported that the 25-year-old mother of three worked, on average, an 80 hour…

A: Claim : the mean work week has increased for women

Q: Find the standard deviation for this data set. if a one goal hockey game was added to this data set,…

A: From the plot representing the number of goals scored per game, there are three games in which three…

Q: In a study of Ridge View's boys' basketball team, the average height is 68 inches and standard…

A: Given that, In a study of Ridge view's boys' basketball team, the average height is 68 inches and…

Q: If the mean of a set score is 65 and the standard deviation is 15, what is the zscore of a person…

A: The z-score of a random variable x is defined as follows: z = (x – µ)/σ. Here, µ and σ are the mean…

Inverse Normal Distribution

The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.

Mean, Median, Mode

It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.

Z-Scores

A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.