# Statistics Help Now

##### Question 1 of 23
1.0 Points
The chi-square goodness-of-fit test can be used to test for:

##### Question 2 of 23
1.0 Points
A company operates four machines during three shifts each day. From production records, the data in the table below were collected. At the .05 level of significance test to determine if the number of breakdowns is independent of the shift.

 Machine Shift A B C D 1 41 20 12 16 2 31 11 9 14 3 15 17 16 10
 Part 2 of 16 –

##### Question 3 of 23
1.0 Points
____________ is/are especially helpful in identifying outliers.

##### Question 4 of 23
1.0 Points
In regression analysis, the variable we are trying to explain or predict is called the

##### Question 5 of 23
1.0 Points
In a simple linear regression analysis, the following sum of squares are produced: = 500 = 100 = 400

The proportion of the variation in Y that is explained by the variation in X is:

 Part 3 of 16 –

##### Question 6 of 23
1.0 Points
Which of the following statements is true regarding the F – distribution?

##### Question 7 of 23
1.0 Points
Serum ferritin is used in diagnosing iron deficiency. In a study conducted recently researchers discovered that in a sample of 28 elderly men the sample standard deviation of serum ferritin was 52.6 mg/L. For 26 younger men the sample standard deviation was 84.2 mg/L. At the .01 level of significance, do these data support the conclusion that the ferritin distribution in elderly men has a smaller variance than in younger men?

 Part 4 of 16 –

##### Question 8 of 23
1.0 Points
Which of the following values is not typically used for ?

##### Question 9 of 23
1.0 Points
Smaller p-values indicate more evidence in support of the:

##### Question 10 of 23
1.0 Points
In an article appearing in
Today’s Health a writer states that the average number of calories in a serving of popcorn is 75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a random sample of 20 servings of popcorn and computed the sample mean number of calories per serving to be 78 with a sample standard deviation of 7.

Compute the z or t value of the sample test statistic.

 Part 5 of 16 –

##### Question 11 of 23
1.0 Points
The average gas mileage of a certain model car is 26 miles per gallon. If the gas mileages are normally distributed with a standard deviation of 1.3, find the probability that a randomly selected car of this model has a gas mileage between 25.8 and 26.3 miles per gallon.

##### Question 12 of 23
1.0 Points
A sample of 23 European countries found that the variance of life expectancy was 7.3 years. What is the 95% confidence interval estimate for the variance of life expectancy in Europe?

 Part 6 of 16 –

##### Question 13 of 23
1.0 Points
The normal distribution is:

 Part 7 of 16 –

##### Question 14 of 23
1.0 Points
The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.

 x 0 1 2 3 4 5 P (X=x) 0.2 0.25 0.2 0.15 0.1 0.1

Find P(1 < X < 5)

 Part 8 of 16 –

##### Question 15 of 23
1.0 Points
A furniture manufacturer offers bookcases in 5 different sizes and 3 different colors. If every color is available in every size, then the total number of different bookcases is

 Part 9 of 16 –

##### Question 16 of 23
3.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation).
NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A sport preference poll yielded the following data for men and women. Use a 5% significance level and test to determine if sport preference and gender are independent.

Sport Preferences of Men and Women
Men 20 25 30 75
Women 18 12 15 45
38 37 45 120

What is the test value for this hypothesis test?

What is the critical value for this hypothesis test?

What is the conclusion for this hypothesis test?  Choose one.

1.  There
is sufficient evidence to support the claim that one’s sport preference is dependent on one’s gender.
2. There
is not sufficient evidence to support the claim that one’s sport preference is dependent on one’s gender.