Answer:
[22.57 ± 2.776]
Step-by-step explanation:
Hello!
You have the 95% Confidence Z-interval (21.182;23.958), the mean X[bar]= 22.57 and the sample size n=25.
The formula for the Z interval is
[X[bar] ± ]
The value of Z comes from tha standard normal table:
The semiamplitude (d) or margin of error (E) of the interval is:
E or d= (Upperbond- Lowerbond)/2 = (23.958-21.182)/2 = 2.776
[X[bar] ± E]
[22.57 ± 2.776]
I hope it helps!
Answer: 6
Step-by-step explanation:
Total buttons in the bag= 24
%of large button is 25%
0.25*24=6
Number of large button is 6
Answer:
There were 693 students before the increase.
Step-by-step explanation:
You just take 90 percent of 770, which is 770 * 0.90 = 693.
Answer:
b=3
Step-by-step explanation:
2b+4b=12
6b^2=12
6b^2 - 6 =12 - 6
b^2/2=6/2
b=3