The mean life of a television set is 123 months with a standard deviation of 19 months. If a sample of 55 televisions is randomly selected, what is the probability that the sample mean would differ from the true mean by greater than 1.2 months? I just need help getting from 1 - P (-0.47 < z < 0.47) to the answer. In my lesson it says the next step is 0.3192 but I have NO CLUE where that number comes from. Please help me! Thank you!

1- P(-0.47 < z < 0.47) = 0.63836

Step-by-step explanation:

Here, we want to get the answer to;

1-P ( -0.47 < z < 0.47)

Mathematically, we are going to use the standard normal distribution table for this

Let us try to evaluate;

P(-0.47 < z < 0.47)

Mathematically, that will be;

P (z < 0.47) - P(z < -0.47)

where P (z < -0.47) = P( z > 0.47)

so we have

P(-0.47 < z < 0.47) = P(z < 0.47) - P(z > 0.47)

So we have this using the standard normal distribution table as follows;

0.68082 - 0.31818 = 0.36164

Now, we can insert this in the earlier expression of;

1- P(-0.47 < z < 0.47)

= 1-0.36164 = 0.63836

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.

step by step explanation: when u removing the parentheses and combined them that would be : x+3y-x-y=2y