Step-by-step explanation:
9 ≤ |4x + 7|
9 ≤ 4x + 7
9 - 7 ≤ 4x
2 ≤ 4x
2/4 ≤ x
<h2>
1/2 ≤ x</h2>
9 ≤ |4x + 7|
9 ≤ -(4x + 7)
9 ≤ -4x - 7
9 + 7 ≤ -4x
16 ≤ - 4x
16/-4 ≤ x
<h2>-
4 ≤ x </h2>
<h2>
{-4 ≤ x ≤ 1/2} </h2>
Answer:
30%
Step-by-step explanation:
II started by multiplying 19*15% and then kept going from 15 to 20 to 25 then to 30 and it was right
Answer: 0.2
Step-by-step explanation:
What is between 3x and 24?
Answer:
90% confidence interval for the mean is between a lower limit of 3.08 days and an upper limit of 3.18 days.
Step-by-step explanation:
Confidence interval is given as mean +/- margin of error (E)
mean = 3.13 days
sd = 0.48 day
n = 250
degree of freedom = n-1 = 250-1 = 249
confidence level (C) = 90% = 0.9
significance level = 1 - C = 1 - 0.9 = 0.1 = 10%
critical value (t) corresponding to 249 degrees of freedom and 10% significance level is 1.65153
E = t×sd/√n = 1.65153×0.48/√250 = 0.05 day
Lower limit of mean = mean - E = 3.13 - 0.05 = 3.08 days
Upper limit of mean = mean + E = 3.13 + 0.05 = 3.18 days
90% confidence interval is (3.08, 3.18)
