A study is to be carried out that requires 90% confidence of estimating the proportion of students who study over 3 hours per day to within0.035 How large the sample size of students should be for such estimation?

The critical value is( )[correct to 4 decimal places].

According to the formula ( )

the required sample size is at least( )[correct to 2 decimal places].

Therefore, the required sample size is( )

(2)A researcher plans to estimate the mean score of statistics exam of a population of students to within19 marks at 98% confidence level. The standard deviation of the examination score of the population is 24.82. What is the sample size required?

The critical value is( )[correct to 4 decimal places].

According to the formula( )

he required sample size is at least( )[correct to 2 decimal places].

Therefore, the required sample size is( )

I want the whole calculate progess.