Answer:
The answer to the question is;
Yes, it is very significant as the number of of observed vaccinated children is below the number of actually vaccinated children by 78.
Step-by-step explanation:
The result of the survey of more than 13,000 children indicate that only 89.4 % had actually been and the P-value indicate that the chance of having a sample proportion of 89.4 % vaccinated is 1.1 %.
P is low at 0.011 for which however the proportion of those vaccinated is between 0.889 and 0.899 using a 95% confidence interval, whereby the decrease from 90 % believed to 89.9 % is small, albeit it depends on the size of the population.
At 89.4 %, in a sample of 13,000, the number of children expected to have been vaccinated but were missed is equal to 90 - 89.4 = 0.6 % = 0.006
Therefore the children missed = 78 children which is significant.