Answer:
The probability that <em>X</em> is less than 42 is 0.1271.
Step-by-step explanation:
The random variable <em>X </em>follows a Normal distribution.
The mean and standard deviation are:
E (X) = <em>μ</em> = 50.
SD (X) = <em>σ</em> = 7.
A normal distribution is continuous probability distribution.
The Normal probability distribution with mean µ and standard deviation σ is given by,

To compute the probability of a Normal random variable we first standardize the raw score.
The raw scores are standardized using the formula:

These standardized scores are known as <em>z</em>-scores and they follow normal distribution with mean 0 and standard deviation 1.
Compute the probability of (X < 42) as follows:

*Use a <em>z</em>-table for the probability.
Thus, the probability that <em>X</em> is less than 42 is 0.1271. 
The normal curve is shown below.
 
        
             
        
        
        
It’s the first one -13–16
        
             
        
        
        
Answer:
There is a 95% confidence that the true mean height of all male student at the large college is between the interval (63.5, 74.4).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for population mean is:

The (1 - α)% confidence interval for population parameter implies that there is a (1 - α) probability that the true value of the parameter is included in the interval.
Or, the (1 - α)% confidence interval for the parameter implies that there is (1 - α)% confidence or certainty that the true parameter value is contained in the interval.
The 95% confidence interval for the average height of male students at a large college is, (63.5 inches, 74.4 inches).
The 95% confidence interval for the average height of male students (63.5, 74.4) implies that, there is a 0.95 probability that the true mean height of all male student at the large college is between the interval (63.5, 74.4).
Or, there is a 95% confidence that the true mean height of all male student at the large college is between the interval (63.5, 74.4).
 
        
             
        
        
        
Answer:
66-4y
Step-by-step explanation:
(11x3 – 2y)2 
= (33 -2y)2
= 66-4y
 
        
                    
             
        
        
        
Answer:
12 - (⅛)π cm²
Step-by-step explanation:
Rectangle + circle - semicircle
(4 × 3) + (pi × 1²) - ½(pi × 1.5²)
12 + pi(1 - 9/8)
12 - (⅛)π