Answer:
f= -15
Step-by-step explanation:
u just have to divide
-75/5= -15 so f equal -15
Answer:
<h2>The correct answer for this question is 78.</h2>
Step-by-step explanation:
- The average or mean of any variable or mathematical phenomenon is calculated as the division of the sum of all the numbers or items within the particular variable by the total number of items or numbers within the variable.
- In this case, the marks of the 4 exams in the semester are 77,90,85 and 100 respectively.There are total 5 exams in the semester.
- Let's suppose that the marks for the 5th exam is x.
- Therefore, based on the mathematical formula to compute average or mean,to get an overall average of 86 including all the 5 exams, one has to get:-
![\frac{77+90+85+100+x}{5}=86](https://tex.z-dn.net/?f=%5Cfrac%7B77%2B90%2B85%2B100%2Bx%7D%7B5%7D%3D86)
![77+90+85+100+x=430](https://tex.z-dn.net/?f=77%2B90%2B85%2B100%2Bx%3D430)
![x=430-77-90-85-100](https://tex.z-dn.net/?f=x%3D430-77-90-85-100)
![x=78](https://tex.z-dn.net/?f=x%3D78)
- Hence, based on the above calculations,one has has to get 78 on the 5th exam to obtain an overall average of exactly 86.
The number 100 and that’s the only one I can think of
Answer:
do R-P-R-S-P-P-R-P
Step-by-step explanation:
Answer:
atleast 385
Step-by-step explanation:
Given that an electrical power company is looking to expand into a new market. Before they commit to supplying the new area with electricity, they would like know the mean daily power usage for homes there.
Population std deviation = ![\sigma = 50](https://tex.z-dn.net/?f=%5Csigma%20%3D%2050)
Sample size =![n](https://tex.z-dn.net/?f=n)
STd error of sample mean = ![\frac{50}{\sqrt{n} }](https://tex.z-dn.net/?f=%5Cfrac%7B50%7D%7B%5Csqrt%7Bn%7D%20%7D)
Margin of error for 95% would be Critical value ( std error)
Here since population std dev is known we can use Z critical value= 1.96
![1.96*\frac{50}{\sqrt{n} }19.6^2\\n>384.16](https://tex.z-dn.net/?f=1.96%2A%5Cfrac%7B50%7D%7B%5Csqrt%7Bn%7D%20%7D%3C5%5C%5Cn%3E19.6%5E2%5C%5Cn%3E384.16)
Sample size should be atleast 385