Business Statistic Questions 1-15

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Business Statistic Questions 1-15

Question 1

  1.  

    For the interval estimation of μ when σ is known and the sample is large, the proper distribution to use is

    the normal distribution

    the t distribution with n degrees of freedom

    the t distribution with n + 1 degrees of freedom

    the t distribution with n + 2 degrees of freedom

    

Question 2

  1.  

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

    confidence level

    interval estimate

    parameter value

    population estimate

    

Question 3

  1.  

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

    confidence level

    margin of error

    parameter estimate

    interval estimate

    

Question 4

  1.  

    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?

    standard distribution

    z distribution

    alpha distribution

    t distribution

    

Question 5

  1.  

    The z value for a 97.8% confidence interval estimation is

    2.02

    1.96

    2.00

    2.29

    

Question 6

  1.  

    The t value for a 95% confidence interval estimation with 24 degrees of freedom is

    1.711

    2.064

    2.492

    2.069

    

Question 7

  1.  

    As the sample size increases, the margin of error

    increases

    decreases

    stays the same

    increases or decreases depending on the size of the mean

Question 8

  1.  

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

    confidence level

    degrees of freedom

    precise value of the population mean μ

    degrees of freedom minus 1

    

Question 9

  1.  

    In general, higher confidence levels provide

    wider confidence intervals

    narrower confidence intervals

    a smaller standard error

    unbiased estimates

    

Question 10

  1.  

    An interval estimate is a range of values used to estimate

    the shape of the population’s distribution

    the sampling distribution

    a sample statistic

    a population parameter

    

Question 11

  1.  

    As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution

    becomes larger

    becomes smaller

    stays the same

    becomes negative

    

Question 12

  1.  

    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

    22

    23

    60

    61

    

Question 13

  1.  

    After computing a confidence interval, the user believes the results are meaningless because the width of the interval is too large. Which one of the following is the best recommendation?

    Increase the level of confidence for the interval.

    Decrease the sample size.

    Increase the sample size.

    Reduce the population variance.

    

Question 14

  1.  

    A sample of 225 elements from a population with a standard deviation of 75 is selected. The sample mean is 180.The 95% confidence interval for μ is

    105.0 to 225.0

    175.0 to 185.0

    100.0 to 200.0

    170.2 to 189.8

    

Question 15

  1.  

    The sample size needed to provide a margin of error of 2 or less with a .95 probability when the population standard deviation equals 11 is

    10

    11

    116

    117