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:
The length of each side of the city is 250b
Step-by-step explanation:
Given
--- tree distance from north gate
--- movement from south gate
--- movement in west direction from (b)
See attachment for illustration
Required
Find x
To do this, we have:
--- similar triangles
So, we have the following equivalent ratios

Where:

Substitute these in the above equation


Express as fraction


Cross multiply

Open bracket

Rewrite as:

Expand

Factorize

Factor out x + 284

Split

Solve for x

x can't be negative;
So:

Answer:x=3
Step-by-step explanation:x squared is one x.you then add the X's to get 2x.then you subtract the five on the other side to get 2x=6.after you get that you divide both sides by 2 to get x=3
B .....................................................
For the first 60 positive integers, a = 1, n = 60, l = 60.
Sn = n/2(a + l)
s = 60/2(1 + 60) = 30(61)
For the next 60 positive integer, a = 61, n = 60, l = 120
Sum = 60/2(61 + 120) = 30(61 + 120) = 30(61) + 30(120) = s + 3600
Sum of first 120 positive integers = s + s + 3600 = 2s + 3600