Answer:
after 21 seconds
Step-by-step explanation:
Given
h = - 16t² + 272t + 1344
When the ball strikes the ground then h = 0, that is
- 16t² + 272t + 1344 = 0 ( divide through by - 16 )
t² - 17t - 84 = 0 ← in standard form
(t - 21)(t + 4) = 0 ← in factored form
Equate each factor to zero and solve for t
t - 21 = 0 ⇒ t = 21
t + 4 = 0 ⇒ t = - 4
However t > 0 thus t = 21
The ball strikes the ground after 21 seconds.
150 because 6 times 5 is 30 then you multiply whats inside the square root thing so you'd get 25, 25 is a perfect square which simplifies to 5 then 5 times 30 is 150.
2000 grams. 1 kilogram = 1000 grams
Answer:
Step-by-step explanation:
The formula for determining confidence interval is expressed as
Confidence interval
= mean ± z × s/ √n
Where
z is the value of the z score
s = standard deviation
n = sample size
a) The 95% confidence level has a z value of 1.96
The 99% confidence level has a z value of 2.58
Since 99% confidence level z value is greater than 95% confidence level z value, if we input it into the formula, it will result to a higher confidence interval. So changing from a 95% confidence level to a 99% confidence level would make a confidence interval wider.
b) The √15 is smaller than the √350. This means that if we make use of the formula, √350 will give a lower confidence interval than that of √15. Therefore, the confidence interval would be narrower changing from a sample size of 15 to a sample size of 350.
c) Applying the formula, a standard deviation of 15 pounds would result to a lower confidence interval than a standard deviation of 20 pounds. Therefore, the confidence interval would be wider changing from a standard deviation of 15 pounds to a standard deviation of 20 pounds.
Answer:
aw thank you sm <3 !!! needed to hear that
Step-by-step explanation:
