Answer:
0.72secs
Step-by-step explanation:
Given the height of the ball in air modeled by the equation:
h=−16t²+23t+4
Required
Total time it spent in the air
To get this we need to calculate its time at the maximum height
At the maximum height, 
v = dh/dt = 0
-32t + 23 = 0
-32t = -23
t = 23/32
t = 0.72secs
<em>Hence the total time it spend in the air will be 0.72secs</em>
 
        
             
        
        
        
Answer:
1. 
2. 
Step-by-step explanation:
Given
Variation: inverse Proportion
y = 7, x = 9
Required
- Write an equation connecting y and x
- Find y when x = 21
Given that thee variation is inversely proportional;
This implies that

Convert variation to equation
 ----------- Equation 1
 ----------- Equation 1
Where k is the constant of variation
Substitute 7 for y and 9 for x in equation 1

Multiply both sides by 9


Substitute 63 for k in equation 1

Multiply both sides by x


Hence, the equation connecting x and y is 
Solving for when x = 21
Substitute 21 for x in the above equation

Divide both sides by 21


 
        
             
        
        
        
Answer:
0.4077
Step-by-step explanation:
It's important to use parenthesis to avoid confusion.
9^(2x) = 6
Use exponent properties:
(9^2)^x = 6
81^x = 6
Take log of both sides
ln(81^x) = ln(6)
Use log properties:
x ln(81) = ln(6)
Solve for x:
x = ln(6) / ln(81)
x ≈ 0.4077
 
        
             
        
        
        
Answer: The probability that 3 or more of the next 5 customers will order chocolate is 30%.  3/10
Sandy conducted her own experiment to answer this question. She observed what groups of 5 customers ordered. In her experiment, 30% of the time at least 3 of the customers ordered chocolate.
The fraction 30% is 3/10.