# Mathematics

1. What is it called when chance produces a sample statistic that is not equal to the population parameter it represents?

a null result | ||

sampling error | ||

an alternative result | ||

experimenter error |

**5 points **

**Question 2**

1. A Type II error means that we’ve claimed that there is no relationship between 2 variables when really a relationship exists.

True | ||

False | ||

**5 points **

**Question 3**

1. Andy is conducting a study of whether adolescent males who are enrolled in an anger-management class exhibit more aggressive behaviors than other adolescent boys. For the test of aggression Andy has chosen to use a population mean of 57 and standard deviation of 7. He collects data on a sample of 25 boys in the anger-management class and obtains a sample mean of 60. Calculate the z obt.

1.40 | ||

There’s not enough information to find the z obt | ||

2.14 | ||

1.645 |

**5 points **

**Question 4**

1. Andy is conducting a study of whether adolescent males who are enrolled in an anger-management class exhibit more aggressive behaviors than other adolescent boys. For the test of aggression Andy has chosen to use a population mean of 57 and standard deviation of 7. He collects data on a sample of 25 boys in the anger-management class and obtains a sample mean of 60. Should he do a one or two tailed test?

one tailed | ||

two tailed | ||

**5 points **

**Question 5**

1. If we retain the null, we have significant results.

True | ||

False | ||

**5 points **

**Question 6**

1. You hypothesize that children will be more relaxed when they are tested with their mothers present. On a standard test, the national average score of children tested without their mother present is 44 and the standard deviation is 6.32. You test the relaxation of children when their mother is present. Using the sample data below, complete all the steps of a z test and tell me if having the mother present increases a child’s relaxation score.

50 52 68 28 66 59 44 36 32 26 42 40 44 42 68 60

Can’t solve this problem. | ||

Obtained a z of -2.09. The mother’s presence does not increase a child’s relaxation score. | ||

Obtained a z of +2.09. The mother’s presence does increase a child’s relaxation score. | ||

Obtained a z of 1.58. The mother’s presence does not effect the child’s score. |

**5 points **

**Question 7**

1. Andy is conducting a study of whether adolescent males who are enrolled in an anger-management class exhibit more aggressive behaviors than other adolescent boys. For the test of aggression Andy has chosen to use a population mean of 57 and standard deviation of 7. He collects data on a sample of 25 boys in the anger-management class and obtains a sample mean of 60. What should Andy conclude?

The results are not significant. This means that adolescent males enrolled in these classes do exhibit increased aggressive behaviors. | ||

The results are not significant. This means that adolescent males enrolled in these classes do not exhibit increased aggressive behaviors. | ||

The results are significant. This means that adolescent males enrolled in these classes do not exhibit increased aggressive behaviors. | ||

The results are significant. This means that adolescent males enrolled in these classes do exhibit increased aggressive behaviors. |

**5 points **

**Question 8**

1. If we reject the H0, we have convincing evidence that the predicted relationship exists.

True | ||

False | ||

**5 points **

**Question 9**

1. If the z obt does not lie beyond the z crit (farther away from the population mean) in the sampling distribution, we should

reject the null | ||

retain the null | ||

conclude that our experimental treatment worked | ||

not reject the alternative |

**5 points **

**Question 10**

1. Andy is conducting a study of whether adolescent males who are enrolled in an anger-management class exhibit more aggressive behaviors than other adolescent boys. For the test of aggression Andy has chosen to use a population mean of 57 and standard deviation of 7. He collects data on a sample of 25 boys in the anger-management class and obtains a sample mean of 60. Using an alpha level of .05, what is the z crit?

1.645 | ||

There’s no way to look this up. | ||

2.346 | ||

1.96 |