Construct a 95 confidence interval for the population mean, . Assume the population has a normal distribution. A sample of 20 part-time workers had mean annual earnings of 3120 with a standard deviation of 677.
Round to the nearest dollar.
A) (2135, 2567 ) B) (1324, 1567 ) C) (2657, 2891 ) D) (2803, 3437 )
Q. 2Determine whether or not the following events are mutually exclusive. One person is randomly selected from a church congregation: the person is female, the person is over 55 years of age.
A) not mutually exclusive B) cannot be determined C) mutually exclusive
Q. 3A social researcher in a particular school district wishes to obtain information on the number of school-age children (ages 6-17 ) per family.
A random sample of 250 households was selected from the district's records. Each was contacted and asked how many school-age children were in the household. Identify the data collection method.
A) designed experiment B) survey
C) observational study D) published source
Q. 4When using interval data, one cannot
A) set up inequalities. B) form differences. C) divide. D) do any of these.
Q. 5A computer package was used to generate the following printout for estimating the sale price of condominiums in a particular neighborhood.
X = sale_price
SAMPLE MEAN OF X = 46,400
SAMPLE STANDARD DEV = 13,747
SAMPLE SIZE OF X = 15
CONFIDENCE = 98
UPPER LIMIT = 55,713.80
SAMPLE MEAN OF X = 46,400
LOWER LIMIT = 37,086.20
What assumptions are necessary for any inferences derived from this printout to be valid?
A) The sample variance equals the population variance.
B) The population mean has an approximate normal distribution.
C) The sample was randomly selected from an approximately normal population.
D) All of these are necessary.
Q. 6College students' spending A consumer group wants to see if a new education program will improve the spending habits of college students. Students in an economics class are randomly assigned to three different courses on spending habits.
a.
What are the experimental units?
b. How many factors are there?
c. How many treatments are there?
d. What is the response variable?
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