Answer:
He needs 7 more consecutive successful first serves to raise his first serve percentage to 60%.
Step-by-step explanation:
After n consecutive serves, his total number of serves is going to be n+8, since he has already served 8 times. In the best case, his number of successful first serves is n+2.
His percentage of succesful first serves is the division of the number of succesful first serves divided by the total number of serves. So

We want
. So







He needs 7 more consecutive successful first serves to raise his first serve percentage to 60%.
square root(-108) - square root(-3) =8.66025404 i
x = 30
The distributive property says that we need to multiply what's in the brackets by 1/2 (so 1/2*x and 1/2*6) to get the equation 1/2x + 3 = 18.
Then we need to subtract our constant, 3, from boths sides to get 1/2x = 15.
Multiply both sides by two to isolate x and you get x = 30.
Hope this helps! :)
Answer:
Confidence Interval = (23.776, 24.224)
Step-by-step explanation:
Restaurant chain claims that its bottles of ketchup contain 24 ounces of ketchup on average.
⇒ Mean = 24 ounces.
Standard Deviation = 0.8
Number of bottles used for sample = 49
⇒ n = 49
Confidence level = 95%
Corresponding z value with 95% confidence level = 1.96
Now, confidence interval is given by the following expression :

Hence, Confidence Interval = (23.776, 24.224)