A sample of 29 boxes of cereal has a sample standard deviation of 0.81 ounces. Construct a 95% confidence interval to estimate the true standard deviation of the filling process for the boxes of cereal. a. ( 0.427,1.144)
b. (0.515,1.105)
c. (0.726,0.726)

The 95% confidence interval is  

Step-by-step explanation:

From the question we are told that

   The sample size is  n = 29

    The sample standard deviation is

  Generally the 95% confidence interval to estimate the true standard deviation  is mathematically represented as  

Generally from the  chi -distribution table  the critical value of at a degree of freedom of    is  

Generally from the  chi -distribution table  the critical value of at a degree of freedom of    is  

So

=>              

75 tickets have been sold so far.

step-by-step explanation:

in this question it is clearly mentioned that 45 children's tickets have been sold and this number is 60% of the total tickets sold.

now let's assume the total number of tickets sold be x.

then 60% of x = 45

⇒

⇒ x(.6) = 45

by dividing with .6 on both the sides of the equation

⇒ x = 75

therefore 75 tickets have been sold so far.