1.2 Skills practice exam 3: chapters 7, 8, 9, & 10  (Page 2/2)

The null hypothesis is“the percentage of men who score 45 points or more (out of 50 points) on a statistics test at De Anza College is the same as the percentage of women who score 45 points or more.”The alternate hypothesis is“the percentage of men who score 45 points or more (out of a 50 point test) on a statistics test at De Anza College is more than the percentage of women who score 45 points or more.”

The appropriate hypothesis test to perform and distribution to use is

• A

  a test of two population proportions, independent groups; Student-t distribution

• B

  a test of a single population proportion; Normal distribution

• C

  a test of two population means, independent groups; Normal distribution

• D

  a test of two population proportions, independent groups; Normal distribution

The correct null hypothesis for this test is

• A

  m ${}^3$ 1786

• B

  m£2000

• C

  m ${}^3$ 2000

• D

  m<2000

At a 5% level of significance (a), the correct decision for this hypothesis test is

• A

  reject $H_{\mathrm{o}}$ because a is more than the p-value.

• B

  reject $H_{\mathrm{o}}$ because a is less than the p-value.

• C

  do not reject $H_{\mathrm{o}}$ because a is more than the p-value.

• D

  do not reject $H_{\mathrm{o}}$ because a is less than the p-value.

The appropriate distribution for this test is

• A

  Normal with standard deviation $937

• B

  t with degrees of freedom = 15

• C

  t with degrees of freedom = 14

• D

  Normal with standard deviation $241.93

The distribution of the average wait times is:

• A

  N( 10 , 1. 0050 )

• B

  U( 0 , 20 )

• C

  N( 10 , 5.7735)

• D

  Exp ( 1 20 )

The probability that the average wait time is no more than 15 minutes is

• A

  1

• B

  0. 7500

• C

  0. 7769

• D

  0

Which probability statement best describes the graph? The horizontal axis has the label Xbar.

• A

  P( Xbar>6 )

• B

  P( Xbar<3 )

• C

  P( Xbar>6 or X<3 )

• D

  P( 3<Xbar<6 )

The hypothesis test is:

• A

  right - tailed

• B

  left - tailed

• C

  two–tailed

• D

  no-tailed

The correct conclusion is:

• A

  The percentage of U.S. adults that have Internet access is not one-half.

• B

  more than half of all U.S. adults have Internet access.

• C

  half of all U.S. adults have Internet access.

• D

  less than half of all U.S. adults have Internet access.

What type of hypothesis test is conducted?

• A

  Test of a single population mean

• B

  Test of two population proportions, independent groups

• C

  Matched or Paired Samples

• D

  Test of two population means, independent groups

Select the appropriate alternate hypothesis.

• A

  µd£0

• B

  µd>0

• C

  µd>2.2

• D

  µd£2.2

What is the correct conclusion?

• A

  The organic fertilizer does result in more blossoms per stalk

• B

  The organic fertilizer does not result in more blossoms per stalk.

• C

  The organic fertilizer results in the same number of blossoms per stalk

• D

  The conventional chemical fertilizer does result in more blossoms per stalk

The median age, in years, is:

• A

  39

• B

  22.6

• C

  19.5

• D.

  There is not enough information.

If 100 residents are surveyed, the IQR for the average age is:

• A

  0. 30

• B

  30.5

• C

  3.04

• D.

  There is not enough information.

What is the probability that 50 randomly selected teenagers spend, on average, between 15 and 30 minutes cleaning their rooms each week?

• A

  0.7500

• B

  0.2902

• C

  0.2492

• D

  0.9612

Find the 70th percentile for the average amount of time 50 teenagers spend cleaning their rooms each week.

• A

  70

• B

  21.5

• C

  30.5

• D

  7.1