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:
B
Step-by-step explanation:
(x+7)(x+5)
Answer:
9.9 years
Step-by-step explanation:
A = P e ^(rt)
Where A is the amount in the account
P is the amount invested
R is the interest rate
t is the time
P = 8500
r =7% = .07
A = 17000
Substituting into the equation
17000=8500 e^(.07t)
Divide each side by 8500
17000/8500=8500/8500 e^(.07t)
2 = e^(.07t)
Take the natural log of each side
ln (2) = ln e^(.07t)
ln(2) = .07t
Divide each side by .07
ln(2)/.07 = .07t/.07
ln(2)/.07 = t
9.902102579=t
Rounding to one decimal place
9.9 years
Answer: I believe it’s C
Step-by-step explanation: I hope i’m right
Answer:
y=4x-5.
Step-by-step explanation:
slop-interception form of the required line is y=kx+b, where k - slop, b - intercept;
1) to find value of k:
if the required line is parallel to the given line, then slop of the given line = slop of the required line, it means k=4 and the required line is y=4x+b;
2) to find the value of 'b':
if to substitute the given coordinates into the equation of the given line, then:
15=4*5+b, b= -5.
3) finally, y=4x-5
