In a population of fish, approximately 42% are female. A test is conducted to see if, in
fact, the proportion is less. State the null and alternative hypotheses
Ans
H0: p = 0.42
Ha: p < 0.42
The mean entry level salary of an employee at a company is $58,000. You believe it is
higher for IT professionals in the company. State the null and alternative hypotheses.
Ans
H0: = 58,000
Ha: > 58,0
The American family has an average of two children. What is the random variable? Describe in words.
Ans
The random variable is the mean number of children an American family has.
You are testing that the mean speed of your cable Internet connection is more than
three Megabits per second. State the null and alternative hypotheses.
Ans
H0: 3 Ha: > 3
For Exercise 9.12, what are and in words?
Ans
= the probability that you think the bag cannot withstand -15 degrees F, when in fact it can = the
probability that you think the bag can withstand -15 d
Which distribution do you use when the standard deviation is not known and you are testing one
population mean? Assume sample size is large.
Ans
Use a Students t-distribution.
The probability of winning the grand prize at a particular carnival game is 0.005. Michele wins the grand
prize. Is this considered a rare or common event? Why?
Ans
This is considered a rare event bec
In words, describe 1 for Exercise 9.12.
Ans
1 is 1 the probability of a Type II error. It represents the power of the test. A valid test will have a
high power; therefore, a low probability of a Type
It is believed that Lake Tahoe Community College (LTCC) Intermediate Algebra students
get less than seven hours of sleep per night, on average. A survey of 22 LTCC Intermediate
Algebra students genera
A group of doctors is deciding whether or not to perform an operation. Suppose the null hypothesis, H0,
is: the surgical procedure will go well. State the Type I and Type II errors in complete sentenc
A sleeping bag is tested to withstand temperatures of -15 F. You think the bag cannot stand
temperatures that low. State the Type I and Type II errors in complete sentences.
Ans
Type I: The bag can wi
The mean price of mid-sized cars in a region is $32,000. A test is conducted to see if the claim is true.
State the Type I and Type II errors in complete sentences.
Ans
Type I: The mean price of mid-s
A random survey of 75 death row inmates revealed that the mean length of time on death row is 17.4
years with a standard deviation of 6.3 years. If you were conducting a hypothesis test to determine i
A sociologist claims the probability that a person picked at random in Times Square in New York City is
visiting the area is 0.83. You want to test to see if the claim is correct. State the null and a
A sociologist claims the probability that a person picked at random in Times Square in
New York City is visiting the area is 0.83. You want to test to see if the proportion is
actually less. What is t
A group of doctors is deciding whether or not to perform an operation. Suppose the null hypothesis, H0,
is: the surgical procedure will go well. Which is the error with the greater consequence?
Ans
Th
A microbiologist is testing a water sample for E-coli. Suppose the null hypothesis, H 0, is: the
sample does not contain E-coli. The probability that the sample does not contain E- coli, but the
micro
A microbiologist is testing a water sample for E-coli. Suppose the null hypothesis, H0, is: the sample
contains E-coli. Which is the error with the greater consequence?
Ans
A Type I error has the grea
A statistics instructor believes that fewer than 20% of Evergreen Valley College (EVC) students attended
the opening night midnight showing of the latest Harry Potter movie. She surveys 84 of her stud
A group of divers is exploring an old sunken ship. Suppose the null hypothesis, H0, is: the sunken ship
does not contain buried treasure. State the Type I and Type II errors in complete sentences
Ans
The mean age of graduate students at a University is at most 31 y ears with a standard deviation of two
years. A random sample of 15 graduate students is taken. The sample mean is 32 years and the sam