WASHINGTON (CNN) – Illinois Sen. Barack Obama pulled support from
virtually all sectors of the voting public Tuesday on his way to defeating
rival Sen. Hillary Clinton in the Virginia, Maryland and Washington, D.C.,
Democratic primaries, according to CNN exit polling.
Obama was expected to poll well among young voters, independents and
African-Americans, and he did – taking 60 to 70 percent of the votes in the
first two groups and nearly 90 percent of black voters, the polls suggest.
But he also was edging out Clinton among voters 65 and older, blue-collar
workers and women, all groups that Clinton was counting on as the core of
her support.
Early exit polling by CNN was done with a sample of 1,246 Democratic
voters in Virginia. Among those polled, Obama was winning with 61
percent of the vote to Clinton’s 37 percent. In Maryland, 1,245 voters were
polled, and Obama won among them, 62 percent to 35 percent.
CNN did not conduct exit polling in Washington, D.C.
Voters who described themselves as independents made up 22 percent of
those who cast a ballot in Virginia’s Democratic primary and 13 percent in
Maryland, according to the polling. Those voters favored Obama by a
margin of 66 percent to 33 percent in Virginia and 68 to 24 in Maryland.
Virginia has an open primary system that allows voters to choose a
primary without declaring themselves a member of either party.
“Obama is drawing a lot of independents -- that is a legitimate claim,” said
University of Virginia political scientist Larry Sabato. “But to suggest that
an enormous number of Republicans are changing party registrations and
coming to his banner just isn’t true.”
But there was a slight uptick in what the Illinois senator has dubbed
“Obamacans” on Tuesday. Seven percent of voters in the Virginia primary
described themselves as Republicans -- and 70 percent of those polled voted
for Obama.
According to CNN exit polling, 3 percent of people who voted in Democratic
primaries on Super Tuesday described themselves as Republicans – most
of them backing Obama. That same percentage of Maryland voters in
Tuesday’s Democratic contest identified themselves with the GOP.
Close to 90 percent of Tuesday’s black voters polled said they voted for
Obama, a native of Hawaii whose father is Kenyan and mother is from
Kansas. African-Americans made up 29 percent of voters in the Democratic
primary, according to the early polling.
Do a statistical test to verify if CNN’s exit poll shows that voters in
Virginia and Maryland had the same voting pattern? What’s your
conclusion? (20%)
WASHINGTON (CNN) – Illinois Sen. Barack Obama pulled support from
virtually all sectors of the voting public Tuesday on his way to defeating
rival Sen. Hillary Clinton in the Virginia, Maryland and Washington, D.C.,
Democratic primaries, according to CNN exit polling.
Obama was expected to poll well among young voters, independents and
African-Americans, and he did – taking 60 to 70 percent of the votes in the
first two groups and nearly 90 percent of black voters, the polls suggest.
But he also was edging out Clinton among voters 65 and older, blue-collar
workers and women, all groups that Clinton was counting on as the core of
her support.
Early exit polling by CNN was done with a sample of 1,246 Democratic
voters in Virginia. Among those polled, Obama was winning with 61
percent of the vote to Clinton’s 37 percent. In Maryland, 1,245 voters were
polled, and Obama won among them, 62 percent to 35 percent.
CNN did not conduct exit polling in Washington, D.C.
Voters who described themselves as independents made up 22 percent of
those who cast a ballot in Virginia’s Democratic primary and 13 percent in
Maryland, according to the polling. Those voters favored Obama by a
margin of 66 percent to 33 percent in Virginia and 68 to 24 in Maryland.
Virginia has an open primary system that allows voters to choose a
primary without declaring themselves a member of either party.
“Obama is drawing a lot of independents -- that is a legitimate claim,” said
University of Virginia political scientist Larry Sabato. “But to suggest that
an enormous number of Republicans are changing party registrations and
coming to his banner just isn’t true.”
But there was a slight uptick in what the Illinois senator has dubbed
“Obamacans” on Tuesday. Seven percent of voters in the Virginia primary
described themselves as Republicans -- and 70 percent of those polled voted
for Obama.
According to CNN exit polling, 3 percent of people who voted in Democratic
primaries on Super Tuesday described themselves as Republicans – most
of them backing Obama. That same percentage of Maryland voters in
Tuesday’s Democratic contest identified themselves with the GOP.
Close to 90 percent of Tuesday’s black voters polled said they voted for
Obama, a native of Hawaii whose father is Kenyan and mother is from
Kansas. African-Americans made up 29 percent of voters in the Democratic
primary, according to the early polling.
For the Virginia and Maryland Democratic primary elections, suppose
all voters would either vote for Clinton or Obama. Furthermore,
suppose Clinton could attract 60% of all the non-African-American
voters to back her. Who would have a lead on the primary? By how
many percent points? (8%)
As a first step, one needs to set up a null hypothesis and an
alternative hypothesis. Please show the correspondence between the
two types of hypotheses and the following situations. Please write the
two types of hypotheses on the left and the corresponding situations
on the right. (10%)
A) Nothing is present.
B) The treatment has an effect.
C) Something is wrong with the process.
D) The status quo is valid.
E) New method shows an improvement.
What is the probability of rejecting a good lot of products? What is the
probability of rejecting a bad lot of products? What kind of error has
been committed for these two cases? (12%)
可觀看題目詳解,並提供模擬測驗!(免費會員無法觀看研究所試題解答)