Answer:
1) There are 13 students in Jerry's study. 
2) There are 39 students in Kathy's study. 
3) Jerry's study is more trustworthy! 
Step-by-step explanation:
1) Jerry's study is the one with the dot plot.
Now, the number of students is calculated by adding the total number of dots in the plot.
We have a total of 13 dots. 
Thus, there are 13 students in Jerry's study.
2) Kathy's study is the one with the histogram.
The total number of students is gotten by adding the corresponding number of students on the y-axis for each range of distance on the x-axis.
Total number of students = 9 + 11 + 7 + 12 = 39 students
3) Jerry's study where he used a dot plot is likely to be more trustworthy because it gives exact values of the number of students for each distance represented whereas, Kathy's study where she used a histogram doesn't give exact values but just gives a range of distances for a particular number of people. 
 
        
             
        
        
        
Answer:
40 grams of 13% alcohol solution and 10 grams of 18% alcohol solution.
Step-by-step explanation:
13%(x) + 18%(50-x) = 14%*50g   Multiply them all
0.13x + (9-0.18x) = 7 
0.13x-0.18x + 9 = 7   Simplify the equation and subtract 0.13x from 0.18x
9-0.05x = 7   Add 0.05x to each side
9 = 7+0.05x   Subtract 7 from both sides
0.05x = 2   Multiply each side by 100
5x = 200   Divide both sides by 5
x = 40 
50 - 40 = 10 
40 grams and 10 grams
Your welcome
 
        
                    
             
        
        
        
Answer:
 x = 2
Step-by-step explanation:
-3 = -2x + 1 
minus 1 to the both sides 
-3 -1 = -2x
-4 = -2x
divide both sides by -2
x = 2
 
        
             
        
        
        
Answer:
The second one (2) is a lie
Step-by-step explanation:
The quantities are all proportional, with 4 donuts costing one dollar being consistant. With this, we can multiply the amount of donuts to 40, and through what we know, we can find that the donuts will cost 10 dollars. This leaves only (2) left.
 
        
                    
             
        
        
        
 Let X be the national sat score. X follows normal distribution with mean μ =1028, standard deviation σ = 92
The 90th percentile score is nothing but the x value for which area below x is 90%.
To find 90th percentile we will find find z score such that probability below z is 0.9
P(Z <z) = 0.9
Using excel function to find z score corresponding to probability 0.9 is
z = NORM.S.INV(0.9) = 1.28
z =1.28
Now convert z score into x value using the formula
x = z *σ + μ
x = 1.28 * 92 + 1028
x = 1145.76
The 90th percentile score value is 1145.76
The probability that randomly selected score exceeds 1200 is
P(X > 1200) 
Z score corresponding to x=1200 is
z = 
z = 
z = 1.8695 ~ 1.87
P(Z > 1.87 ) = 1 - P(Z < 1.87)
Using z-score table to find probability z < 1.87
P(Z < 1.87) = 0.9693
P(Z > 1.87) = 1 - 0.9693
P(Z > 1.87) = 0.0307
The probability that a randomly selected score exceeds 1200 is 0.0307