B. 5
Each row across (left to right) adds up to 43
The confidence interval formula is computed by:
Xbar ± Z s/ sqrt (n)
Where:
Xbar is the mean
Z is the z value
S is the standard deviation
N is the number of samples
So our given are:
90% confidence interval with a z value of 1.645
Sample size 40, 45
Mean 180, 179
Standard deviation 2, 4
So plugging that information in the data will give us a
confidence interval:
For 1:
Xbar ± Z s/ sqrt (n)
= 180 ± 1.645 (2 / sqrt (40))
= 180 ± 1.645 (0.316227766)
= 180 ± 0.520194675
= 179.48, 180.52
For 2:
Xbar ± Z s/ sqrt (n)
= 179 ± 1.645 (4 / sqrt (45))
<span>= 179 ± 1.645 (0.596284794)</span>
therefore, the answer is letter b
So the actual meal was at most 130 dollars they paid minus the 20 dolars tip: 130-20=110 dollars.
it was 5 people: Dolores+5 friends, who presumably all paid the same (buffet).
then we have to divide the 110 among the 5 people: it's 110/5=22
so each of them paid at most 22 dollars:
x (the amount they paid)≤22
Answer:
k = 0.25
Step-by-step explanation:
The standard equation of a proportional relationship is
y = kx ← k is the constant of proportion
y = 0.25x ← is in this form
with k = 0.25
