A meteorological office keeps records of the annual precipitation in different cities. For one city, the mean annual precipitation is 25.2 and the standard deviation of the annual precipitation amounts is 3.7.
Let x represent the annual precipitation in that city. Determine the z-score for an annual precipitation in that city of 24.8 inches. Round your final answer to two decimal places.
A) -0.11 B) 0.84 C) 13.51 D) 0.11
Q. 2100,000 randomly selected adults were asked whether they drink at least 48 oz of water each day and only 45 said yes. Identify the sample and population.
A) Sample: the 45 of adults who drink at least 48 oz of water; population: all adults
B) Sample: the 100,000 selected adults; population: the 45 of adults who drink at least 48 oz of water
C) Sample: all adults ; population: the 100,000 selected adults
D) Sample: the 100,000 selected adults; population: all adults
Q. 3Lengths of pregnancies are normally distributed with a mean of 268 days and a standard
deviation of 15 days. (a) Find the probability of a pregnancy lasting more than 250 days.
(b) Find the probability of a pregnancy lasting more than 280 days.
Draw the diagram for
each and discuss the part of the solution that would be different to finding the requested
probabilities.
Q. 4A variable x has a mean, , of 13.3 and a standard deviation, , of 5.5. Determine the z-score corresponding to an observed value for x of 10.6. Round your final answer to two decimal places.
A) 4.35 B) 0.49 C) 0.38 D) -0.49
Q. 5An employee at the local ice cream parlor asks three customers if they like chocolate ice cream. Identify the sample and population.
A) Sample: the 3 selected customers; population: the customers who like chocolate ice cream
B) Sample: the 3 selected customers; population: all customers
C) Sample: all customers; population: the 3 selected customers
D) Sample: the customers who like chocolate ice cream; population: all customers
Q. 6The number of books sold over the course of the four-day book fair were 194, 197, 247,
and 76. Assume that samples of size 2 are randomly selected with replacement from this
population of four values.
List the different possible samples, and find the mean of each of
them.
Q. 7Suppose that you roll a die and record the number that comes up and then flip a coin and record whether it comes up heads or tails. One possible outcome can be represented as 2H (a two on the die followed by heads).
Make a list of all the possible outcomes. What is the probability that you get tails and an even number? What assumption are you making when you find this probability?
Q. 8The mean of a set of data is 380.65 and its standard deviation is 82.45. Find the z-score for a value of 405.71. Round your final answer to two decimal places.
A) 0.60 B) 0.27 C) 0.30 D) 0.33
Q. 9A magazine publisher always mails out a questionnaire six months before a subscription ends. This questionnaire asks its subscribers if they are going to renew their subscriptions.
On average, only 8 of the subscribers respond to the questionnaire. Of the 8 who do respond, an average of 41 say that they will renew their subscription. This 8 who respond to the questionnaire are known as what?
A) The population B) The sample
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