Norfolk's under-performing schools prompt inspections
Under-performing schools in Norfolk have prompted watchdog Ofsted to send in inspectors.
Figures for last November show that only 54% of county pupils attend secondary schools rated good or better.
Nationally on average, 71% of secondary schools are rated good or better. The county council said it is committed to improving education.
The figures also show 63% of primary age children go to schools rated good or better, compared to 74% nationally.
The county's schools are also underperforming compared to the similar authority of Cornwall.
In August 2012, only 47% of Norfolk secondary schools were rated good or outstanding, compared with 80% of Cornish schools.
While no secondary schools in Cornwall were rated as inadequate, 11% of these schools were inadequate in Norfolk.
Sean Harford, Ofsted regional director for the East of England, said: "Every parent wants their child to go to a good or better school. However, in Norfolk a little over half of secondary school age children and only 63% of primary school children currently do so.
"It cannot be right that local authority areas with similar demographics - such as the size of the population and the levels of deprivation - have such varying levels of provision in schools.
"That is why we are carrying out focused school inspections across under-performing areas, where we will be looking not just at the performance of the individual schools but also the support they are receiving from their local authority."
He told the BBC that if inspectors, after talking to the school and governors, found "sufficient concern raised about the authority, we will look at the authority itself, look at advisory work by the local authority".
Gordon Boyd, children's services assistant director, said: "The county council shares parents' aspirations for their children and recognises employers' need for young people to have better skills and qualifications. Our aim is to see standards in our schools improve and many more rated 'good' or 'outstanding.
"Though overall educational attainment among our children and young people is lower than the national average, it is improving."