h8st4ts grade A Q&A
You look at real estate ads for houses in Sarasota, Florida. Many houses range from
$200,000 to $400,000 in price. The few houses on the water, however, have prices up
to $15 million. Which of the following statements best describes the distribution of home
prices in Sarasota? - (correct answer)(d) The distribution is most likely skewed to the
right, and the mean is greater than the median.
A child is 40 inches tall, which places her at the 90th percentile of all children of similar
age. The heights for children of this age form an approximately Normal distribution with
a mean of 38 inches. Based on this information,what is the standard deviation of the
heights of all children of this age? - (correct answer)(e) 1.56 inches
A large set of test scores has mean 60 and standard deviation 18. If each score is
doubled, and then 5 is subtracted from the result, the mean and standard deviation of
the new scores are - (correct answer)(b) mean 115; std. dev. 36
For a certain experiment, the available experimental units are eight rats, of which four
are female (F1, F2, F3, F4) and four are male (M1, M2, M3, M4). There are to be four
treatment groups, A, B, C, and D. If a randomized block design is used, with the
experimental units blocked by gender, which of the following assignments of treatments
is impossible? - (correct answer)(c) A → (F1, M2), B → (F3, F2), C → (F4, M1), D →
(M3, M4)
For a biology project, you measure the weight in grams (g) and the tail length in
millimeters (mm) of a group of mice. The equation of the least-squares line for predicting
tail length from weight is predicted tail length = 20 + 3 × weight Which of the following is
not correct? - (correct answer)(a) The slope is 3, which indicates that a mouse's weight
should increase by about 3 grams for each additional millimeter of tail length.
The figure below shows a Normal density curve. Which of the following gives the best
estimates for the mean and standard deviation of this Normal distribution? - (correct
answer)(c) μ = 225, σ = 50
, The owner of a chain of supermarkets notices that there is a positive correlation
between the sales of beer and the sales of ice cream over the course of the previous
year. During seasons when sales of beer were above average, sales of ice cream also
tended to be above average. Likewise, during seasons when sales of beer were below
average,sales of ice cream also tended to be below average. Which of the following
would be a valid conclusion from these facts? - (correct answer)(e) The positive
correlation is most likely a result of the lurking variable temperature; that is, as
temperatures increase, so do both beer sales and ice cream sales.
Here are the IQ scores of 10 randomly chosen fifth-grade students:145 139 126 122
125 130 96 110 118 118
Which of the following statements about this data set is not true? - (correct answer)(e) If
the value 96 were removed from the data set, the IQR of the remaining 9 IQ scores
would be lower than the IQR of all 10 IQ scores.
Before he goes to bed each night, Mr. Kleen pours dishwasher powder into his
dishwasher and turns it on. Each morning, Mrs. Kleen weighs the box of dishwasher
powder. From an examination of the data, she concludes that Mr. Kleen dispenses a
rather consistent amount of powder each night. Which of the following statements is
true?
I. There is a high positive correlation between the number of days that have passed
since the box of dishwasher powder was
opened and the amount of powder left in the box.
II. A scatter plot with days since purchase as the explanatory variable and amount of
dishwasher powder used as the response variable would display a strong positive
association.
III. The correlation between the amount of powder left in the box and the amount of
powder used should be −1. - (correct answer)(d) II and III only
You look at real estate ads for houses in Sarasota, Florida. Many houses range from
$200,000 to $400,000 in price. The few houses on the water, however, have prices up
to $15 million. Which of the following statements best describes the distribution of home
prices in Sarasota? - (correct answer)(d) The distribution is most likely skewed to the
right, and the mean is greater than the median.
A child is 40 inches tall, which places her at the 90th percentile of all children of similar
age. The heights for children of this age form an approximately Normal distribution with
a mean of 38 inches. Based on this information,what is the standard deviation of the
heights of all children of this age? - (correct answer)(e) 1.56 inches
A large set of test scores has mean 60 and standard deviation 18. If each score is
doubled, and then 5 is subtracted from the result, the mean and standard deviation of
the new scores are - (correct answer)(b) mean 115; std. dev. 36
For a certain experiment, the available experimental units are eight rats, of which four
are female (F1, F2, F3, F4) and four are male (M1, M2, M3, M4). There are to be four
treatment groups, A, B, C, and D. If a randomized block design is used, with the
experimental units blocked by gender, which of the following assignments of treatments
is impossible? - (correct answer)(c) A → (F1, M2), B → (F3, F2), C → (F4, M1), D →
(M3, M4)
For a biology project, you measure the weight in grams (g) and the tail length in
millimeters (mm) of a group of mice. The equation of the least-squares line for predicting
tail length from weight is predicted tail length = 20 + 3 × weight Which of the following is
not correct? - (correct answer)(a) The slope is 3, which indicates that a mouse's weight
should increase by about 3 grams for each additional millimeter of tail length.
The figure below shows a Normal density curve. Which of the following gives the best
estimates for the mean and standard deviation of this Normal distribution? - (correct
answer)(c) μ = 225, σ = 50
, The owner of a chain of supermarkets notices that there is a positive correlation
between the sales of beer and the sales of ice cream over the course of the previous
year. During seasons when sales of beer were above average, sales of ice cream also
tended to be above average. Likewise, during seasons when sales of beer were below
average,sales of ice cream also tended to be below average. Which of the following
would be a valid conclusion from these facts? - (correct answer)(e) The positive
correlation is most likely a result of the lurking variable temperature; that is, as
temperatures increase, so do both beer sales and ice cream sales.
Here are the IQ scores of 10 randomly chosen fifth-grade students:145 139 126 122
125 130 96 110 118 118
Which of the following statements about this data set is not true? - (correct answer)(e) If
the value 96 were removed from the data set, the IQR of the remaining 9 IQ scores
would be lower than the IQR of all 10 IQ scores.
Before he goes to bed each night, Mr. Kleen pours dishwasher powder into his
dishwasher and turns it on. Each morning, Mrs. Kleen weighs the box of dishwasher
powder. From an examination of the data, she concludes that Mr. Kleen dispenses a
rather consistent amount of powder each night. Which of the following statements is
true?
I. There is a high positive correlation between the number of days that have passed
since the box of dishwasher powder was
opened and the amount of powder left in the box.
II. A scatter plot with days since purchase as the explanatory variable and amount of
dishwasher powder used as the response variable would display a strong positive
association.
III. The correlation between the amount of powder left in the box and the amount of
powder used should be −1. - (correct answer)(d) II and III only
