I need to find the critical value of what I have here so far, and I am stuck can someone please help ASAP ?

Percent of children depressed: 4.3%
1250= n
4.3/100= s/1250
53.75= sample mean
n=sample size
After, mid 2010:
Percent of children depressed: 5%
100= n
5/100= s/100
5= sample mean
n= sample size
Null hypothesis: p= 0.043
Alternative hypothesis: p> 0.043
q= 1-p= 1- .05= .95
z= (.05-.043)/ sq rt(.043*.95/1250)
z= 1.224

To find the critical value, you need to determine the significance level or the desired level of confidence for your hypothesis test. The critical value is then obtained from a standard normal distribution table or calculated using a statistical software.

Assuming you want to perform a hypothesis test at a significance level of α=0.05 (which is commonly used), the critical value corresponds to the z-score that marks the α/2 (0.025) area in the upper tail of the standard normal distribution.

To find the critical value using the z-score, you can follow these steps:

1. Look for the value of α/2 in the standard normal distribution table (z-table). For α=0.05, α/2=0.025, so we need to find the z-score that corresponds to the cumulative probability of 0.975 (1 - α/2) in the upper tail.

2. Look for the closest value to 0.975 in the z-table. Typically, you will find two values with equal probabilities on either side of 0.975. In this case, the closest values are 0.9750 and 0.9751.

3. Determine the corresponding z-score for the closest value found. For example, if you find that the z-score associated with 0.9750 is 1.96, then the critical value at a significance level of 0.05 would be z=1.96.

It's important to note that the critical value may vary depending on the desired significance level or level of confidence chosen for your hypothesis test. Additionally, the method for finding the critical value may differ depending on the statistical software or standard normal distribution table you are using.