Well, the first 20 questions are certainly good ones, for a basic stats quiz.

Seriously, learn about the standard normal curve, and you will have about 12 of them answered.

mgfcortez wrote:

this is the problem a friend has been having a hard time with studying for her statistics for health services test.

i offered to help even tho I'm not too smart.lol

i was thinking i could just look it up on Google but I've been at it for 12 hours or more now.

and ever time i think i have the right answers for one i read something else that makes me think its wrong so.

well i really got myself into something way over my head here in this statistics stuff:(

so please if i could get the answers from some of you smart ppl^_^

she still needs to study it tomorrow even when she gets the answers because her test is Monday.lol

and she can't just turn this in but if she fails all that money she payed for school is wasted, she works a lot so her studying has really suffered because of it.

i wish i had more time to learn statistics so i could help but i only had today and all night.lol

so i really hope someone can help her i really want to help so i'll give somebody $20 tonight threw pay pal if you give me the answers to this test and will give you more on pay day!

well here's the statistics for health services test please i need this before 1pm central time tomorrow when i go to work:P

thanks so much!

multiple choice

1. the center of a normal curve is.

a. always equal to zero

b. is the mean of the distribution

c. cannot be negative

d. is the standard deviation

2. a normal distribution with a mean of 0 and a standard deviation of 1 is called.

a. a probability density function

b. an ordinary normal curve

c. a standard normal distribution

d.none of these alternatives is correct

3. the z score for the standard normal distribution

a. is always equal to zero

b. can can never be negative

c. can be either negative or positive

d. is always equal to the mean

4. in a standard normal distribution, the probability that z is greater than 0.5 is

a. 0.5

b. equal to 1

c. at least 0.5

d. 1.96

5.a negative value of z indicates that

a. the number of standard deviations of an observation is to the right of the mean

b. the number of standard deviations of an observation is to the left of the mean

c. a mistake has been made in computations, since z cannot be negative

d. the data has a negative mean

6. for the standard normal probability distribution, the area to the left of the mean is

a. -0.5

b. 0.5

c. any value between 0 to 1

d. 1

7. which of the following is not a characteristic of the normal probability distribution?

a. the mean, median, and the mode are equal

b. the mean of the distribution can be negative, zero, or positive

c. the distribution is symmetrical

d. the standard deviation must be 1

8. larger values of the standard deviation result in a normal curve that is

a. shifted to the right

b. shifted to the left

c. narrower and more peaked

d. wider and flatter

9. for a normal distribution, a negative value of z indicates

a. a mistake has been made in computations, because z is always positive

b. the area corresponding to the z is negative

c. the z is to the left of the mean

d. the z is to the right of the mean

10. the standard deviation of a standard normal distribution

a. is always equal to zero

b. is always equal to one

c. can be any positive value

d. can be any value

11. if the mean of a normal distribution is negative,

a. the standard deviation must also be negative

b. the variance must also be negative

c. a mistake has been made in the computations, because the mean of a normal distribution cannot be negative

d. none of these alternatives is correct.

12. the highest point of a normal curve occurs at

a one standard deviation to the right of the mean

b. two standard deviations to the right of the mean

c. approximately three standard deviations to the right of the mean

d. the mean

13. a standard normal distribution is a normal distribution

a. with a mean of 1 and a standard deviation of 0

b. with a mean of 0 and a standard deviation of 1

c. with any mean and a standard deviation of 1

d. with any mean and any standard deviation

14. sampling distribution of x is the

a. probability distribution of the sample mean

b. probability distribution of the sample proportion

c. mean of the sample

d. mean of the population

15. a simple random sample of 100 observations was taken from a large population. the sample mean and the standard deviation were determined to be 80 and 12 respectively. the standard error of the mean is

a. 1.20

b. 0.12

c. 8.00

d 0.80

16. in computing the standard error of the mean, the finite population correction factor is used when

a. N/n>0.05

b. N/n<0.05

_

c. n/N>0.05

d.n/N<30

_

17. the closer the sample mean is to the population mean,

a the larger the sampling error

b. the smaller the sampling error

c. the sampling error equals 1

d. none of these alternatives is correct.

18. as the sample size increases, the

a. standard deviation of the population decreases

b. population mean increases

c. standard error of the mean decreases

d. standard error of the mean increases

19 in point estimation

a. data from the population is used to estimate the population parameter

b. data from the sample is used to estimate the population parameter

c. data from the sample is used to estimate the sample statistic

d. the mean of the population equals the mean of the sample

20. the sample statistic s is the point estimator of

a. u

b. o

_

c. x

_

d. p

21.the sample mean is the point estimator of

a. u

b. o

_

c. x

_

d. p

22. the probability distribution of the sample mean is called the

a. central probability distribution

b. sampling distribution of the mean

c. random variation

d. standard error

23. as the sample size becomes larger, the sampling distribution of the sample mean approaches a

a. binomial distribution

b. Poisson distribution

c. normal distribution

d. chi-square distribution

24. the sampling error is the

a. same as the standard error of the mean

b. difference between the value of the sample mean and the value of the population mean

c. error caused by selecting a bad sample

d. standard deviation multiplied by the sample size

25. a population characteristic, such as a population mean, is called

a. a statistic

b. a parameter

c. a sample

d. the mean deviation

26. a sample statistic, such as a sample mean, is known as

a. a statistic

b. a parameter

c. the mean deviation

d. the central limit theorem

27. a theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the

a. approximation theorem

b. normal probability theorem

c. central limit theorem

d. central normality theorem

28. the purpose of statistical inference is to provide information about the

a. sample based upon information contained in the population

b. population based upon information contained in the sample

c. population based upon information contained in the population

d. mean of the sample based upon the mean of the population

29. as the sample size increases, the variability among the sample means

a. increases

b. decreases

c. remains the same

d. depends upon the specific population being sampled

30. the absolute value of the difference between the point estimate and the population parameter it estimates is

a. the standard error

b. the sampling error

c. precision

d. the error of confidence

31. when s is used to estimate o, the margin of error is computed by using

a. normal distribution

b. t distribution

c. the mean of the sample

d. the mean of the population

32. in order to determine an interval for the mean of a population with unknown standard deviation a sample of 61 items is selected. the mean of the sample is determined to be 23. the number of degrees of freedom for reading the t value is

a. 22

b. 23

c. 60

d. 61

33. if we want to provide a 95% confidence interval for the mean of a population, the confidence coefficient is

a. 0.485

b. 196

c. 0.95

d. 1.645

34. as the number of degrees of freedom for a t distribution and the standard normal distribution

a. becomes larger

b. becomes smaller

c. stays the same

d. none of these alternatives is correct.

35. for the interval estimation of u when o is known and the sample is large, the proper distribution to use is

a. the normal distribution

b. the t distribution with n degrees of freedom

c. the t distribution with n + 1 degrees of freedom

d. the t distribution with n + 2 degrees of freedom

36. an estimate of a population parameter the provides an interval of values believed to contain the value of the parameter is known as the

a. confidence level

b. interval estimate

c. parameter value

d. population estimate

37. the value added and subtracted from a point estimate in order to develop an interval estimate of the population parameter is known as the

a. confidence level

b. margin of error

c. parameter estimate

d. interval estimate

38. whenever the population standard deviation is unknown and the population has a normal or near-normal distribution, which distribution is used in developing an interval estimation

a. standard distribution

b. z distribution

c. alpha distribution

d. t distribution

39. in interval estimation, the t distribution is applicable only when

a. the population has a mean of less than 30

b. the sample standard deviation is used to estimate the population standard deviation

c. the variance of the population is known

d. the standard deviation of the population is known

40. in developing an interval estimate, if the population standard deviation is unknown

a. it is impossible to develop an interval estimate

b.the standard deviation is arrived at using the range

c. the sample standard deviation can be used

d. it is assumed the the population standard deviation is 1

41. the ability of an interval estimate to contain the value of the population parameter is described by the

a. confidence level

b. degrees of freedom

c. precise value of the population mean u

d. degrees of freedom minus 1

section B: calculation (clearly show your formula and all the computations):

1. for a sample of 100 students, average (x-bar) blood glucose level is estimated to be 161.84 and the population standard deviation (sigma) is given as 58.15. given a z-value of 1.96, calculate 95% confidence interval for the population mean.

2 for a sample of 25 joggers, average air intake (x-bar) is estimated to be 47.5 and sample standard deviation (s) is given as 4.5. interestingly, the t-value for 24 degrees of freedom equals 2.064. given these data, calculate 95% confidence interval for the population mean.