Answer:
95% confidence interval for the mean number of months is between a lower limit of 6.67 months and an upper limit of 25.73 months.
Step-by-step explanation:
Confidence interval is given as mean +/- margin of error (E)
Data: 5, 15, 12, 22, 27
mean = (5+15+12+22+27)/5 = 81/5 = 16.2 months
sd = sqrt[((5-16.2)^2 + (15-16.2)^2 + (12-16.2)^2 + (22-16.2)^2 + (27-16.2)^2) ÷ 5] = sqrt(58.96) = 7.68 months
n = 5
degree of freedom = n-1 = 5-1 = 4
confidence level (C) = 95% = 0.95
significance level = 1 - C = 1 - 0.95 = 0.05 = 5%
critical value (t) corresponding to 4 degrees of freedom and 5% significance level is 2.776
E = t×sd/√n = 2.776×7.68/√5 = 9.53 months
Lower limit of mean = mean - E = 16.2 - 9.53 = 6.67 months
Upper limit of mean = mean + E = 16.2 + 9.53 = 25.73 months
95% confidence interval is (6.67, 25.73)
Answer:
A) -1
Step-by-step explanation:
We can rewrite 2√5 - 3 as -(3 + 2√5)
Therefore,
We can cancel out 3 + 2√5 both in the numerator and the denominator. So we get
= 1/-1
= -1
Answer : A) -1
Thank you.
Answer:
Snickerdoodles are 0.22$ each and chocolate chip are 0.43$ each
Step-by-step explanation:
using the information in the problem, you can make 2 separate equations: 8x+12y=6.92 and 5x+5y=3.25, let x= the cost of a snickerdoodle and y= the cost of a chocolate chip cookie.
With the 2 equations, we can isolate the y variable of the first equation and simplify which will give us y= -2/3x +6.92/12.
You can now take that equation and plug it into equation number 2:
5x+5(-2/3x + 6.92/12)=3.25.
solve that equation by multiplying 5 through the brackets: 5x-10/3x+34.6/12=3.25
add common terms: 5/3x=4.4/12
find the value of x, you will get x=0.22
plug the value of x (0.22) into one of your equations and solve for the y-value
1/4 off means 0.25 * 28
7
Sale price = 28-7
= 21
