Answer:
$2000
Step-by-step explanation:
let x be the money she invested
lets assume this was for 1 year
0.09(x/2) + 0.07(x/2) = 160
multiply each side by 2 to cancel the denominators:
0.09x + 0.07x = 320
0.16x = 320
x = 2000
 
        
                    
             
        
        
        
Answer:
1) The probability that the mean mpg for a random sample of 25 light vehicles is 0.042341.
2) between 20 and 25 --> 21-25/2.9 = -1.38
Step-by-step explanation:
Problem #1: 
- Using the z-score formula, z = (x-μ)/σ/n, where x is the raw score = 20 mpg,μ is the population mean = 21 mpg , σ is the population standard deviation = 2.9, n = random number of samples.
<h3><u>X < 20</u></h3>
- = z = 20 - 21/2.9/√25
- = z = -1/2.9/5
- = z = -1.72414
<h2><u><em>Now</em></u></h2>
<em>P-value from Z-Table:</em>
<h3><u>P(x<20) = 0.042341</u></h3>
Problem #2: 
<h3>21-25/2.9 = -1.38</h3>
 
        
             
        
        
        
3.73 rounded to the nearest whole number would be 4
        
             
        
        
        
550+40W=S is the equation and after 11 weeks, she would have $990