What is the probability a sample of 66 test takers will provide a sample mean test score within 10 points of the population mean of 533 on the Evidence-based Reading and Writing part of the test?

This question is incomplete, the complete question is;

A certain organization reported the following scores for two parts of the scholastic Aptitude test ( SAT)

Evidence-based Reading and writing  : 533

Mathematics                                           : 527

Assume the population standard deviation for each part is σ = 100.

What is the probability a sample of 66 test takers will provide a sample mean test score within 10 points of the population mean of 533 on the Evidence-based Reading and Writing part of the test?

the required probability is 0.582

Step-by-step explanation:

Given that;

Population mean = 533

sample size n = 66

population standard deviation σ = 100

σ of x bar = 100/√66 = 12.3091

Normal distribution with mean 533 and SD of 12.3091

P( 523 <x< 543 )

Z = 10 / 12.3091

Z = 0.8124, -0.8124

P( z < 0 0.8124) - P( z < -0.8124)      { from table}

⇒  0.7910 - 0.2090

= 0.582

Therefore, the required probability is 0.582

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.