Answer: d. 7 and 1/2 hours
Step-by-step explanation:
Given : The time taken by Ana and Beth do a job together = 3 hours
Time taken by Ana to do a job alone = 5 hours
Let t be the time taken by Beth to do a job .
Then, According to the question ,we have
i.e. Time taken by Beth to do a job =
Hence, the time taken by Beth to do a job alone = 7 and 1/2 hours
Think of it like this, what two numbers when multiplied together, you get 27, and when they add together, you get 12? The answer is 9 and 3,
Your answer here would be (r+9)(r+3) when factored.
Answer:
slope (m) = -8.
Step-by-step explanation:
Slope-intercept form is y = mx + b, in which:
m = slope
b = y-intercept
x = (x , y)
y = (x , y)
~
With the given information on top, it means that -8 is your answer.
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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 ]