Answer:
E
Step-by-step explanation:
Solution:-
- We are to investigate the confidence interval of 95% for the population mean of walking times from Fretwell Building to the college of education building.
- The survey team took a sample of size n = 24 students and obtained the following results:
Sample mean ( x^ ) = 12.3 mins
Sample standard deviation ( s ) = 3.2 mins
- The sample taken was random and independent. We can assume normality of the sample.
- First we compute the critical value for the statistics.
- The z-distribution is a function of two inputs as follows:
- Significance Level ( α / 2 ) = ( 1 - CI ) / 2 = 0.05/2 = 0.025
Compute: z-critical = z_0.025 = +/- 1.96
- The confidence interval for the population mean ( u ) of walking times is given below:
[ x^ - z-critical*s / √n , x^ + z-critical*s / √n ]
Answer: [ 12.3 - 1.96*3.2 / √24 , 12.3 + 1.96*3.2 / √24 ]
Answer:
i am really not sure because i worked it out but i needed to see how they said it .
Step-by-step explanation:
6.40x+9.90(154-x)=1230.90
Solve for x
X=84 for child
154-84=70 for adults
Use substitution
Set them equal to each other
-3x + 4 = 3x - 2
Solve the equation
4 = 6x - 2
6x = 6, x = 1
Plug in 1 for any equation to find y
Y = -3(1) + 4
Y = -3 + 4, y = 1
Solution: x = 1, y = 1
