Answer:
-6 < x ≤ 6
Step-by-step explanation:
Answer:
Type A coffee in lbs = 97 lbs
Step-by-step explanation:
Type a = 4.55/lbs = x
type b = 5.70/lbs = y
Total in lbs = 147lbs
total in sales = 726.50
First,
x + y = 147 lbs -------------------equ 1
4.55x + 5.70y = lbs ------------ equ 2
<em>Multiply equ 1 by 4.55</em>
4.55x + 4.55y = 668.85 -------------equ 3
4.55x + 5.70y = 726.50 ------------equ 4
<em>Subtracting equ 3 from equ 4</em>
1.15y = 57.65
y = 50
<em>Substituting y = 50 into equ 1</em>
x + 50 = 147
x = 97
Answer:
B)
Step-by-step explanation:
Answer:
Boxes sold first week = 104
Boxes sold second week =x+5= 104+5=109
Boxes sold third week = 109 times 2= 218
Step-by-step explanation:
Let x be the number of boxes sold in first week
the girls sold 5 more boxes the second week
So number of boxes sold in second week is x+5
they double the sales of the second week for the third week
So number of boxes sold in third week is 2 (x+5)
Total boxes sold is 431



subtract 15 from both sides

divide by 4 on both sides

Boxes sold first week = 104
Boxes sold second week =x+5= 104+5=109
Boxes sold third week = 104 times 2= 218
Answer:
D)Yes, because the difference in the means in the actual experiment was more than two standard deviations from 0.
Step-by-step explanation:
We will test the hypothesis on the difference between means.
We have a sample 1 with mean M1=18.2 (drug group) and a sample 2 with mean M2=15.9 (no-drug group).
Then, the difference between means is:

If the standard deviation of the differences of the sample means of the two groups was 1.1 days, the t-statistic can be calculated as:

The critical value for a two tailed test with confidence of 95% (level of significance of 0.05) is t=z=1.96, assuming a large sample.
This is approximately 2 standards deviation (z=2).
The test statistict=2.09 is bigger than the critical value and lies in the rejection region, so the effect is significant. The null hypothesis would be rejected: the difference between means is significant.