Answer:
1, 2.2, 5.5, 10.2. 
Step-by-step explanation: these are simplified to the nearest tenth
 
        
                    
             
        
        
        
In such type of questions, all that you are supposed to do is, use basic mathematics to eliminate any one of the given two variables.
Check out the equations if in case you can multiply any of the given ones with a -1 and add the two equations,eliminating one of the variables.
        
                    
             
        
        
        
Answer:
1. 68%
2. 50% 
3. 15/100
Step-by-step explanation:
Here, we want to use the empirical rule 
1. % waiting between 15 and 25 minutes 
From what we have in the question;
15 is 1 SD below the mean 
25 is 1 SD above the mean 
So practically, we want to calculate the percentage between;
1 SD below and above the mean 
According to the empirical rule;
1 SD above the mean we have 34%
1 SD below, we have 34%
So between 1 SD below and above, we have 
34 + 34 = 68%
2. Percentage above the mean 
Mathematically, the percentage above the mean according to the empirical rule for the normal distribution is 50%
3. Probability that someone waits less than 5 minutes 
Less than 5 minutes is 3 SD below the mean
That is 0.15% according to the empirical rule and the probability is 15/100 
 
        
             
        
        
        
Answer:
7 ÷ 4
Step-by-step explanation:
Another example would be:
12/3  = 12 ÷ 3 
The number at the front will be the numerator while the second number will be the denominator
 
        
                    
             
        
        
        
The given sample's confidence interval is 4.73 ± 0.1199, or from 4.61 to 4.85
<h3>What is the z score?</h3>
The z-score is a numerical assessment of a value's connection to the mean of a set of values, expressed in terms of standards from the mean, that is used in statistics.
Given data;
Mean  = 4.73 
Standard deviation  = 0.865
Sample size  = 200
interval  = 95% 
Confidence interval=?
95% of samples contain the population mean (μ) within the confidence interval of 4.73 ± 0.1199.
Hence, the sample's confidence interval is 4.73 ± 0.1199, from 4.61 to 4.85
To learn more about the Z score, refer to; 
brainly.com/question/15016913
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