0.2 Elementary statistics: exam 5: lesson 11

Suppose the random variable X follows a chi-square distribution with degrees of freedom equal to 35. Fill in the blanks.

• A

  $m=$

• B

  $s=$

Check all that apply.

• A

  The chi-square graph always has the same shape.

• B

  If X follows a chi-square distribution with df = 200, then X approximately follows a normal distribution.

• C

  The chi-square distribution is skewed to the right if the degrees of freedom are less than 90.

• D

  The test statistic for the chi-square distribution may be zero.

• E

  A goodness-of-fit hypothesis test is always right-tailed.

• F

  A test of independence tests whether two factors are independent or not.

Write the null and alternate hypotheses for the following:

It is believed that public high school students attend school in equal numbers for each day of the school week. Suppose a sample of the days students were present at school was taken for one particular high school:

• 1750 students were present on Monday
• 1800 students were present on Tuesday
• 1840 students were present on Wednesday
• 1810 students were present on Thursday
• 1800 students were present on Friday

Ho:

Ha: