Foram encontradas 950 questões.
Julgue os itens a seguir, acerca de noções e conceitos de estatística e de tratamento de dados estatísticos.
Verificou-se que, depois de tabular os dados de um experimento, houve necessidade de estabilizar a variância, porque a variância do tratamento na escala original variou diretamente com a média. Nesse caso, deve-se considerar uma transformação logarítmica dos dados.
Provas
Visando investigar o efeito da salinidade do solo no crescimento de determinada vegetação, um pesquisador selecionou tipos diferentes de solo para constituírem os blocos e aplicou seis níveis diferentes de tratamento com sal (15, 20, 30, 35, 45 e 50 ppm). O resultado da análise de variância é mostrado abaixo.
|
fonte |
gl | SQ | QM |
F |
|
modelo |
111,39 |
13,73 |
||
|
erro |
121,7 | |||
|
total corrigido |
23 |
1012,8 |
||
|
trat |
664,4 |
16,38 |
||
|
bloco |
3 |
9,31 |
T test (DMS) para variável: BIOMASSA
Alpha= 0,05; gl= 15; EMS= 8,1118;
valor crítico para T= 2,13;
Diferença Mínima Significativa= 4,2926
| Média | T-Grupo |
N |
|
|
Trat. |
4 | ||
|
20 |
18,100 | A | 4 |
|
15 |
14,150 | A | 4 |
|
30 |
7,475 | B | 4 |
|
35 |
6,000 |
BC | 4 |
|
45 |
5,775 | BC | 4 |
|
50 |
3,075 | C | 4 |
Em relação a essa situação hipotética e aos dados da análise de variância apresentados acima, julgue o item a seguir.
Nessa análise, o erro possui 15 graus de liberdade.
Provas
Julgue os itens a seguir, acerca de noções e conceitos de estatística e de tratamento de dados estatísticos.
Considere que, na pesagem de 30 peixes, obteve-se a média de 30 g e desvio-padrão igual a 2 g. Depois de completar a pesagem, verificou-se que a balança estava descalibrada e que os pesos obtidos estavam 2 g abaixo do peso real. Nessa situação, é correto afirmar que o erro relativo dos dados deve diminuir após a correção dos dados.
Provas
Julgue os itens a seguir, acerca de noções e conceitos de estatística e de tratamento de dados estatísticos.
Considere a seguinte situação hipotética.
Em um experimento, os números de carrapatos observados em cada um dos animais de um grupo, dispostos em ordem crescente, foram iguais a: 4, 7, 7, 9, 10, 11, 13, 15, 15, 15, 17, 17, 19, 19, 20. Após terem sido calculadas a média, a mediana e a moda, um erro foi descoberto: um dos animais com 15 carrapatos tinha, na realidade, 17.
Nessa situação, é correto afirmar que, entre as medidas de tendência citadas, apenas a média deve-se alterar após a correção do dado.
Provas
Julgue os itens a seguir, acerca de noções e conceitos de estatística e de tratamento de dados estatísticos.
Considere-se que, em experimentos com ratos de laboratório, são registrados o sexo e o peso desses animais. O peso é freqüentemente expresso em gramas e o valor registrado é arredondado para o número inteiro mais próximo. Nesse contexto, quanto à classificação dessas variáveis, é correto afirmar que sexo é uma variável discreta e peso é uma variável contínua.
Provas
- Estatística DescritivaMedidas de DispersãoDesvio Médio
- Estatística DescritivaMedidas de Tendência CentralMédias
Julgue os itens a seguir, acerca de noções e conceitos de estatística e de tratamento de dados estatísticos.
Considere-se que, em um experimento, um pesquisador calculou a altura média dos animais que sofriam de uma doença específica. O valor obtido foi igual a 156 cm e o desvio-padrão foi de 5 cm. Investigações posteriores, entretanto, revelaram que todas as medidas feitas estavam 2 cm maiores que os valores verdadeiros. Nessa situação, os valores corretos para a média e o desvio-padrão são 1,54 m e 0,05 m, respectivamente.
Provas
Globalization: The globalization of all aspects of the food
and fiber system is having a sudden and surprising impact on
American agriculture. Profound changes are seen worldwide
from competitive markets around the world, from diseases
not limited to national boundaries, to population growth and
evolving diets. These changes have led to a dramatically new
trade environment, threats of exotic diseases and pests to
domestic production, and international controversies over the
use of biotechnology. To remain competitive, the food and
agriculture sector needs to take these developments into
consideration.
Information Access and Communication: The explosion of
information technology, the worldwide use of the Internet,
and the major advancements of cyberspace communications
are changing the way private industry, government, and
individuals conduct daily business. Vast amounts of
information soon will be available in “real time,” more
people from around the world will be able to retrieve the
information, and advanced computer software will make the
information more useful and meaningful. Advancements in
communication technology offer benefits and opportunities
for everyone involved in the American food and agriculture
sector.
Workforce: A very important employment issue is the need
to recruit and retain a highly skilled and technically well
trained Federal workforce. The relatively low U.S.
unemployment rate makes recruitment highly
competitive. This competitive environment is expected to
require more employer emphasis on recruitment, retention,
student employment, upward mobility, and training/retraining
programs. The public sector will need to recruit a diversity of
people and to maintain a highly qualified and technically
competent workforce. Expanding job opportunities for
women and minorities in science and engineering will help to
tap the Nation’s human potential.
Technology: Advances in technology — such as
bioengineering, precision agriculture, remote sensing, and
decision modeling — can enable agricultural production to
enhance nutrition, protect the environment, and continue to
make the food supply safe. Biotechnology offers great
promise for increasing production efficiency, improving food
quality, and enhancing nutritional value. However, concerns
about genetically modified organisms (GMO) have had a
marked impact on international exports of affected
commodities, and prompted questions about the potential
benefits and risks. Precision agriculture, remote sensing, and
decision modeling will increase production efficiency and
mitigate adverse environmental impacts on agriculture.
Public concern about food safety has led to new rapid
detection technologies that, when fully implemented, will
make the food supply increasingly safer.
Internet: http://www.ars.usda.gov/aboutus/docs.htm?docid=1800 (with adaptations)
In the text,
“However” (l.42) means Nevertheless.
Provas
Globalization: The globalization of all aspects of the food
and fiber system is having a sudden and surprising impact on
American agriculture. Profound changes are seen worldwide
from competitive markets around the world, from diseases
not limited to national boundaries, to population growth and
evolving diets. These changes have led to a dramatically new
trade environment, threats of exotic diseases and pests to
domestic production, and international controversies over the
use of biotechnology. To remain competitive, the food and
agriculture sector needs to take these developments into
consideration.
Information Access and Communication: The explosion of
information technology, the worldwide use of the Internet,
and the major advancements of cyberspace communications
are changing the way private industry, government, and
individuals conduct daily business. Vast amounts of
information soon will be available in “real time,” more
people from around the world will be able to retrieve the
information, and advanced computer software will make the
information more useful and meaningful. Advancements in
communication technology offer benefits and opportunities
for everyone involved in the American food and agriculture
sector.
Workforce: A very important employment issue is the need
to recruit and retain a highly skilled and technically well
trained Federal workforce. The relatively low U.S.
unemployment rate makes recruitment highly
competitive. This competitive environment is expected to
require more employer emphasis on recruitment, retention,
student employment, upward mobility, and training/retraining
programs. The public sector will need to recruit a diversity of
people and to maintain a highly qualified and technically
competent workforce. Expanding job opportunities for
women and minorities in science and engineering will help to
tap the Nation’s human potential.
Technology: Advances in technology — such as
bioengineering, precision agriculture, remote sensing, and
decision modeling — can enable agricultural production to
enhance nutrition, protect the environment, and continue to
make the food supply safe. Biotechnology offers great
promise for increasing production efficiency, improving food
quality, and enhancing nutritional value. However, concerns
about genetically modified organisms (GMO) have had a
marked impact on international exports of affected
commodities, and prompted questions about the potential
benefits and risks. Precision agriculture, remote sensing, and
decision modeling will increase production efficiency and
mitigate adverse environmental impacts on agriculture.
Public concern about food safety has led to new rapid
detection technologies that, when fully implemented, will
make the food supply increasingly safer.
Internet: http://www.ars.usda.gov/aboutus/docs.htm?docid=1800 (with adaptations)
In the text,
“retain” (l.25) is synonymous with detain.
Provas
Globalization: The globalization of all aspects of the food
and fiber system is having a sudden and surprising impact on
American agriculture. Profound changes are seen worldwide
from competitive markets around the world, from diseases
not limited to national boundaries, to population growth and
evolving diets. These changes have led to a dramatically new
trade environment, threats of exotic diseases and pests to
domestic production, and international controversies over the
use of biotechnology. To remain competitive, the food and
agriculture sector needs to take these developments into
consideration.
Information Access and Communication: The explosion of
information technology, the worldwide use of the Internet,
and the major advancements of cyberspace communications
are changing the way private industry, government, and
individuals conduct daily business. Vast amounts of
information soon will be available in “real time,” more
people from around the world will be able to retrieve the
information, and advanced computer software will make the
information more useful and meaningful. Advancements in
communication technology offer benefits and opportunities
for everyone involved in the American food and agriculture
sector.
Workforce: A very important employment issue is the need
to recruit and retain a highly skilled and technically well
trained Federal workforce. The relatively low U.S.
unemployment rate makes recruitment highly
competitive. This competitive environment is expected to
require more employer emphasis on recruitment, retention,
student employment, upward mobility, and training/retraining
programs. The public sector will need to recruit a diversity of
people and to maintain a highly qualified and technically
competent workforce. Expanding job opportunities for
women and minorities in science and engineering will help to
tap the Nation’s human potential.
Technology: Advances in technology — such as
bioengineering, precision agriculture, remote sensing, and
decision modeling — can enable agricultural production to
enhance nutrition, protect the environment, and continue to
make the food supply safe. Biotechnology offers great
promise for increasing production efficiency, improving food
quality, and enhancing nutritional value. However, concerns
about genetically modified organisms (GMO) have had a
marked impact on international exports of affected
commodities, and prompted questions about the potential
benefits and risks. Precision agriculture, remote sensing, and
decision modeling will increase production efficiency and
mitigate adverse environmental impacts on agriculture.
Public concern about food safety has led to new rapid
detection technologies that, when fully implemented, will
make the food supply increasingly safer.
Internet: http://www.ars.usda.gov/aboutus/docs.htm?docid=1800 (with adaptations)
In the text,
“take these developments into consideration” (l.10-11) is the same as take these developments for granted.
Provas
Globalization: The globalization of all aspects of the food
and fiber system is having a sudden and surprising impact on
American agriculture. Profound changes are seen worldwide
from competitive markets around the world, from diseases
not limited to national boundaries, to population growth and
evolving diets. These changes have led to a dramatically new
trade environment, threats of exotic diseases and pests to
domestic production, and international controversies over the
use of biotechnology. To remain competitive, the food and
agriculture sector needs to take these developments into
consideration.
Information Access and Communication: The explosion of
information technology, the worldwide use of the Internet,
and the major advancements of cyberspace communications
are changing the way private industry, government, and
individuals conduct daily business. Vast amounts of
information soon will be available in “real time,” more
people from around the world will be able to retrieve the
information, and advanced computer software will make the
information more useful and meaningful. Advancements in
communication technology offer benefits and opportunities
for everyone involved in the American food and agriculture
sector.
Workforce: A very important employment issue is the need
to recruit and retain a highly skilled and technically well
trained Federal workforce. The relatively low U.S.
unemployment rate makes recruitment highly
competitive. This competitive environment is expected to
require more employer emphasis on recruitment, retention,
student employment, upward mobility, and training/retraining
programs. The public sector will need to recruit a diversity of
people and to maintain a highly qualified and technically
competent workforce. Expanding job opportunities for
women and minorities in science and engineering will help to
tap the Nation’s human potential.
Technology: Advances in technology — such as
bioengineering, precision agriculture, remote sensing, and
decision modeling — can enable agricultural production to
enhance nutrition, protect the environment, and continue to
make the food supply safe. Biotechnology offers great
promise for increasing production efficiency, improving food
quality, and enhancing nutritional value. However, concerns
about genetically modified organisms (GMO) have had a
marked impact on international exports of affected
commodities, and prompted questions about the potential
benefits and risks. Precision agriculture, remote sensing, and
decision modeling will increase production efficiency and
mitigate adverse environmental impacts on agriculture.
Public concern about food safety has led to new rapid
detection technologies that, when fully implemented, will
make the food supply increasingly safer.
Internet: http://www.ars.usda.gov/aboutus/docs.htm?docid=1800 (with adaptations)
Based on the previous text, judge the following items.
Three factors — precision agriculture, remote sensing, and decision modeling — can actually prevent environmental disasters.
Provas
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