A financial analyst wanted to estimate the mean annual return on mutual funds. A random sample of 60 funds' returns shows an average rate of 12%. If the population standard deviation is assumed to be 4%, the 95% confidence interval estimate for the annual return on all mutual funds is
A. 0.037773 to 0.202227
B. 3.7773% to 20.2227%
C. 59.98786% to 61.01214%
D. 51.7773% to 68.2227%
E. 10.988% to 13.012%
Answer: E. 10.988% to 13.012%
Step-by-step explanation:
Given;
Mean x= 12%
Standard deviation r = 4%
Number of samples tested n = 60
Confidence interval is 95%
Z' = t(0.025)= 1.96
Confidence interval = x +/- Z'(r/√n)
= 12% +/- 1.96(4%/√60)
= 12% +/- 0.01214%
Confidence interval= (10.988% to 13.012%)
Rileyflipflop,
![\frac{153}{18}](https://tex.z-dn.net/?f=%20%5Cfrac%7B153%7D%7B18%7D%20)
= 8
![\frac{1}{2}](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B2%7D%20)
, since she can't buy half a CD, she's limited to no more than 8 CDs. If x = the cost of one CD, then x CDs cost $18x. Since we are limited to $153, our equation looks like... 18x < 153x < 8
![\frac{1}{2}](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B2%7D%20)
Again, since we can't buy half a CD, your answer should actually be... x ≤ 8 since we can buy 8 CDs or fewer.
Answer:
Number of quarters → 15
Number of dimes → 2
Step-by-step explanation:
Let the number of dimes I have = y
And number of quarters = x
Since, I have amount in my pocket = $2
Therefore, 0.10y + 0.25x = 2
100(0.10y + 0.25x) = 100×2
25x + 10y = 200
5x + 2y = 40
2y = -5x + 40
y = -2.5x + 20 ---------(1)
Total number of coins in my pocket = 17
x + y = 17
y = -x + 17 ---------(2)
By using a graphing calculator we can graph these two lines (As attached)
Solution of the given system of equations will be the point of intersection of these lines.
Solution → (2, 15)
Number of quarters → 15
Number of dimes → 2
Answer:
The x intercept is (-2,0)
the y intercept is (0,4)