Suponha que uma amostra aleatória simples 
de tamanho 25 seja observada para se testar 
versus 
de uma variável populacional suposta normalmente distribuída com média 
e variância 
Faça 
e 
Nesse caso, a estatística T de teste usual, que tem distribuição t-Student com 24 graus de liberdade sob 
, é dada por
Text II
Examining the fluff that frustrates northern China
Like most blizzards, it begins with just a few white wisps swirling
about. Gradually the volume increases and the stuff starts to
accumulate on the ground. During the heaviest downfalls the air is
so thick with it as to impair visibility. But this is no winter scene. It is
what happens every April across much of northern China, when
poplar trees start giving off their cotton-like seed-pods.
The phenomenon has already begun in Beijing. On April 8th an
eddy of fluff balls wafted around the American treasury secretary,
Janet Yellen, as she held a press conference in an embassy garden.
To call this a nuisance is an understatement. In many people
the fluff triggers allergies, asthma and other respiratory problems.
Experts say the white balls—produced by the trees’ catkins—are
not themselves allergenic, but that they distribute irritating pollen.
They also clog rain gutters, drain pipes and car radiators. Worse,
they pose a fire hazard. Officials have warned that the fuzz balls have
a low ignition point and called for extreme caution on the part of
smokers, welders or anyone inclined to burn them “out of curiosity”.
China’s catkin problem is the unintended consequence of an
old effort to improve the environment. Intensive tree planting
began in the 1950s with the aim of ending the scourge of
sandstorms caused by winds sweeping out of barren areas. The
trees were also meant to firm up the soil and slow desertification.
Poplar trees, along with willows, were selected because they are
cheap, fast-growing and drought-resistant.
In some ways the plan worked. Today sandstorms are less
severe and the threat of desertification has faded. But the annual
onslaught from catkins is another legacy. Female trees are the
cotton-ball culprits. There are millions of them (poplar and willow)
in Beijing alone.
Authorities have sought to mitigate the mess. The simplest way
is to spray water on the trees, turning the fluffy flyers into damp
squibs. More advanced solutions involve “birth control”, or injecting
female trees with chemicals that suppress catkin production.
Another option is “gender-reassignment surgery”, in which branches
on female trees are cut and replaced with male grafts.
But experts say that these efforts will take time. The good
news is that the flurries of poplar fluff will only last for a few more
weeks. The bad news is that wafts of willow fluff will then begin.
From: https://www.economist.com/china/2024/04/18/examining-thefluff-that-frustrates-northern-china
In the last paragraph, the author observes the phenomenon is
João, advogado, constatou a publicação de três acórdãos no âmbito de determinado Tribunal Regional Federal, prolatados em
detrimento do seu cliente e que exauriram a respectiva instância.
Esses acórdãos apresentavam, respectivamente, as características
a seguir.
1º Denegação de mandado de segurança impetrado contra ato de
Juiz Federal, havendo afronta a norma constitucional no
acórdão;
2º Foi julgada válida lei local contestada em face de lei federal; e
3º Foi contrariado tratado internacional.
Ao analisar os recursos cabíveis e as competências do Supremo Tribunal Federal (STF) e do Superior Tribunal de Justiça (STJ), João
concluiu corretamente que, preenchidos os demais requisitos
exigidos,
Sobre os princípios que balizam o processo orçamentário público, assegurando que ele se mantenha alinhado com os objetivos da
Administração Pública, analise as afirmativas a seguir e assinale (V) para a verdadeira e (F) para a falsa.
( ) O Princípio da não afetação prescreve que a lei orçamentária
deve conter todas as receitas e despesas do governo.
( ) O Princípio da universalidade prevê que as receitas e despesas
constarão no orçamento pelos seus totais, vedadas as
deduções.
( ) O Princípio da especificação veda a consignação de dotações
globais para o atendimento de despesas.
As afirmativas são, respectivamente,
Uma ferramenta consagrada na literatura de Finanças para
estimação do custo de captação de recursos é o Custo Médio
Ponderado do Capital (CMPC ou WACC). Formalmente, define-se:
