2 answers:
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Answer:
The standard form of the equation is 49t² - 75t + 3 = 0
The solution of the equations are 1.49 and 0.041
Step-by-step explanation:
* Lets explain how to solve the problem
- The standard form of the quadratic equation is ax² + bx + c = 0,
where a , b , c are constant and a can not be 0
∵ The quadratic equation is -4.9t² + 7.5t + 1.8 = 2.1
- Lets make the left hand side equal to 0
∵ -4.9t² + 7.5t + 1.8 = 2.1 ⇒ subtract 2.1 from both sides
∴ -4.9t² + 7.5t - 0.3 = 0 ⇒ multiply each term by -10
∴ 49t² - 75t + 3 = 0
* The standard form of the equation is 49t² - 75t + 3 = 0
∵ ax² + bx + c = 0
∴ a = 49 , b = -75 , c = 3
- Lets use the formula to solve
the equation
∴
∴
* The solution of the equations are 1.49 and 0.041
Answer:
The proportion is less than 0.75 only
Step-by-step explanation:
given that the ability of auto mechanics to identify simple engine problems, an automobile with a single suchproblem was taken to 72 different car repair facilities.
Sample proportion
Set up hypotheses as
H0: p =0.75
Ha: p < 0.75
(Left tailed test)
Assuming H0 to be true, std error of proportion =
p difference = -0.1667
Test statistic Z = p diff/std error = -2.50
p value = 0.0062
since p is less than0.05 at 5% significance level we reject null hypothesis
The proportion is less than 0.75 only