(a) Which of the following surveys probably would best represent the entire population of households?
25
households within a mile of a park are randomly selected;
12
own a dog.
25
households with a front yard are randomly selected;
11
own a dog.
25
households are randomly selected from the town;
7
own a dog.
(b) There are
650
households in the town.
Using your answer from part (a), estimate the number of households that own a dog.
Based on the information provided, the best survey that would represent the entire population of households is the one where 25 households are randomly selected from the town and 7 of them own a dog. This survey includes households from all areas of the town and doesn't focus on specific criteria such as living near a park or having a front yard.
To estimate the number of households that own a dog, we can use a proportion.
The proportion of households that own a dog in the survey is (7/25) = 0.28.
If we assume that this proportion holds true for the entire population of 650 households, we can estimate the number of households that own a dog by multiplying this proportion by the total population:
0.28 * 650 = 182 households.
Therefore, we estimate that there are approximately 182 households in the town that own a dog.
Northside High wants to estimate the number of seniors who plan to go to a
4
-year college. Answer the following.
(a) Which of the following surveys probably would best represent the entire population of seniors?
50
honor roll students are randomly selected from the senior class;
34
plan to go to a
4
-year college.
50
seniors are randomly selected;
30
plan to go to a
4
-year college.
50
student council members are randomly selected;
45
plan to go to a
4
-year college.
(b) There are
650
seniors at Northside High.
Using your answer from part (a), estimate the number of seniors who plan to go to a
4
-year college.
Based on the information provided, the best survey that would represent the entire population of seniors is the one where 50 seniors are randomly selected and 30 of them plan to go to a 4-year college. This survey includes a random selection of seniors from the entire senior class.
To estimate the number of seniors who plan to go to a 4-year college, we can use a proportion.
The proportion of seniors who plan to go to a 4-year college in the survey is (30/50) = 0.6.
If we assume that this proportion holds true for the entire population of 650 seniors, we can estimate the number of seniors who plan to go to a 4-year college by multiplying this proportion by the total population:
0.6 * 650 = 390 seniors.
Therefore, we estimate that approximately 390 seniors at Northside High plan to go to a 4-year college.
A marketing research company records the consumer habits of a sample of
42
families from a certain community. The table below summarizes the number of gallons of milk consumed by these families during the last month.
Number of families Gallons of milk
8 3
9 4
14 5
11 8
For these families, what is the mean number of gallons of milk consumed last month? Round your answer to at least one decimal place.
gallons
To find the mean number of gallons of milk consumed last month, we need to calculate the sum of all the gallons of milk consumed and divide it by the total number of families.
First, we can find the sum of all the gallons of milk consumed:
(8 * 3) + (9 * 4) + (14 * 5) + (11 * 8) = 24 + 36 + 70 + 88 = 218
Next, we divide this sum by the total number of families to find the mean:
218 / 42 = 5.19
Therefore, the mean number of gallons of milk consumed last month by these families is approximately 5.2 rounded to one decimal place.
The scores on a test for a sample of
35
statistics students are summarized in the following table.
Number of students Score
8 90
16 80
11 70
Find the mean score. Round your answer to at least one decimal place.
To find the mean score, we need to calculate the sum of all the scores and divide it by the total number of students.
First, we can find the sum of all the scores:
(8 * 90) + (16 * 80) + (11 * 70) = 720 + 1280 + 770 = 2770
Next, we divide this sum by the total number of students to find the mean:
2770 / 35 = 79.14
Therefore, the mean score for these statistics students is approximately 79.1 rounded to one decimal place.
The following summarizes the number of fiction books read last summer by a sample of
37
students at a certain college.
Number of students Number of books
2 2
10 3
15 4
10 5
What is the mean number of books read? Round your answer to at least one decimal place.
To find the mean number of books read, we need to calculate the sum of all the number of books read and divide it by the total number of students.
First, we can find the sum of all the number of books read:
(2 * 2) + (10 * 3) + (15 * 4) + (10 * 5) = 4 + 30 + 60 + 50 = 144
Next, we divide this sum by the total number of students to find the mean:
144 / 37 = 3.89
Therefore, the mean number of books read by these students is approximately 3.9 rounded to one decimal place.
An intelligence test was recently administered to a group of
7
people. Their respective completion times (in minutes) were as follows.
27
,
37
,
43
,
37
,
35
,
28
,
37
Send data to calculator
(a) What is the mean of this data set? If your answer is not an integer, round your answer to one decimal place.
(b) What is the median of this data set? If your answer is not an integer, round your answer to one decimal place.
(c) How many modes does the data set have, and what are their values? Indicate the number of modes by clicking in the appropriate circle, and then indicate the value(s) of the mode(s), if applicable.
zero modes
one mode:
two modes: and