High-profile ballot questions that would authorize additional charter schools and legalize the adult use of marijuana have similar levels of "strong support" among likely Massachusetts voters but are backed by "somewhat opposite groups," a new poll found.

Question 2, which would allow state education officials to approve up to 12 new charter schools or expansions per year, has the support of people who identify as conservatives, who earn more than $100,000 per year, and who fall in the age range to 30 to 54 years old, according to the UMass Amherst/WBZ poll.

The poll found that liberals, 18- to 29-year-olds and people earning less than $40,000 annually support Question 4, which would legalize and regulate the use, possession and sale of marijuana for people aged 21 and older.

Fifty-three percent of likely voters support the marijuana question, and 40 percent oppose it, with 7 percent unsure. Including people who are leaning one way or another, support rises to 55 percent and opposition to 42 percent.

On charter schools, 49 percent of likely voters support the question and 39 percent oppose, with 12 percent unsure. With leaners, the support goes up to 52 percent and opposition to 41 percent.

Support is strongest for Question 3, which would restrict farm animal confinement and require eggs sold in Massachusetts to come from hens that have ample room to move around, according to the poll conducted from Sept. 15 to Sept. 20. Seventy-five percent of likley voters said they would vote yes, with 14 percent against the question and 11 percent not sure.

A group called Citizens Against Food Tax Injustice announced its formation Wednesday to oppose Question 3. The group, drawing conclusions based on a California law studied by Cornell University economists, estimated the Massachusetts measure, if adopted, would cost Massachusetts citizens $249 million in higher food prices the first year alone.

The new opposition group counts among its members the Massachusetts Farm Bureau, the National Association of Egg Farmers, the National Pork Producers Council, the New England Brown Egg Council, the Northeast Agribusiness and Feed Alliance, Protect the Harvest and the Retailers Association of Massachusetts.

Twenty-two percent of the 700 likely voters polled were undecided on Question 1, which would authorize an additional slot parlor license in the state. Forty-four percent were in favor and 35 percent against.

Sixty-three percent of respondents said they had a very or somewhat favorable assessment of Gov. Charlie Baker, and the same percentage either strongly or somewhat approve of the way he is doing his job.

Though the first-term Republican governor has not yet said whether he plans to seek re-election in 2018, the poll found he would fare well in potential matchups against some prominent Democrats.

More respondents said they would vote for Baker than U.S. Rep. Katherine Clark (39-24); Newton Mayor Setti Warren (40-17); Attorney General Maura Healey (43-25); Boston Mayor Martin Walsh (37-28); and U.S. Rep. Seth Moulton (39-21).

U.S. Rep. Joe Kennedy III, however, posed a stronger challenge, according to the survey. The same number of registered voters -- 33 percent each -- said they would cast ballots for Baker as Kennedy, with 29 percent unsure and 6 percent saying they would not vote.

Economy and jobs are the top issue facing the state, according to 28 percent of respondents. Twelve percent pegged health care as the most important, with 8 percent naming taxes and another 8 percent naming the federal deficit and government spending. Immigration and education followed at 6 percent each.

Most of the people who said they oppose marijuana legalization -- 36 percent -- did so because it "hurts individuals and society." Fourteen percent said marijuana is a gateway drug and 10 percent said it increases crime or is dangerous.

Among supporters, 30 percent said they favored legalization because marijuana is not as dangerous as other drugs, while 19 percent cited "expensive and problematic" enforcement and 15 percent cited medical benefits.

Great Schools Massachusetts, the coalition supporting the charter school expansion question, said the poll numbers "show voters across Massachusetts believe that every family deserves the right to choose the best public schools for their children."

The coalition on Wednesday also issued a statement praising a new report from the Massachusetts Taxpayers Foundation, which Great Schools Massachusetts spokeswoman Eileen O'Connor said shows that opponents have "built a campaign founded on a lie."

The report found that 3.9 percent of Massachusetts students attended charter schools during the 2016 fiscal year and 3.9 percent of public school funds went to charter schools. According to the Massachusetts Taxpayers Foundation, non-charter school per-pupil spending has grown at a faster rate than charter student spending in some districts, while the reverse is true in other districts, and non-charter school spending has grown despite increased charter enrollment.

"The MTF is the non-partisan gold standard on budget and fiscal matters in the Commonwealth and this study is just the latest in many that have found charter schools have had zero negative impact on district school funding," O'Connor said. "Voters deserve the truth - and the truth is that Question 2 will increase public education funding and give parents more opportunity to choose the best school for their kids."

Opponents of charter school expansion argue that charters siphon away money from public schools that serve a broader swath of the student population, leaving them with fewer funds for fixed costs that do not decrease with enrollment, like building expenses. The Save Our Public Schools campaign, which is opposing Question 2, fired back with its own statement condemning the report and citing the 130 local school committees that have come out against expansion.

"The Massachusetts Taxpayer Foundation, an inherently partisan organization, is simply joining the crowd of outside billionaires funding Question 2 to mislead voters about its grave impact on our public schools. Their so-called report uses select figures from a small number of communities while official state data shows that 231 local school districts will lose more than $450 million to charter schools - this year alone," the statement said. "Right-wing think tanks can fiddle with the numbers all they want, but Massachusetts parents and educators see the impact of this financial drain in classrooms every day: schools without librarians, larger class sizes, school buses eliminated, and other serious cuts."