Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the true population mean textbook weight.
Number of sample, n = 22
Mean, u = 64 ounces
Standard deviation, s = 5.1 ounces
For a confidence level of 90%, the corresponding z value is 1.645. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
64 ± 1.645 × 5.1/√22
= 64 ± 1.645 × 1.087
= 64 ± 1.788
The lower end of the confidence interval is 64 - 1.788 = 62.21 ounces
The upper end of the confidence interval is 64 + 1.788 = 65.79 ounces
Therefore, with 90% confidence interval, the true population mean textbook weight is between 62.21 ounces and 65.79 ounces
[-2 3] times [2
1]
comes out to -2(2)+3(1) = -1. Eliminate the first answer choice, due to
the presence of that -7 instead of -1.
[-2 3] times [0
-3]
comes out to - 9. This matches answer choices #2, #3 and #4.
[3,-4][2
1]
comes out to 6-4, or 2. Matches #2, #3, #4.
[3, -4][0
-3]
comes out to +12, which matches answer choice #4.
Answer choice #4 is the correct one.
Review matrix multiplication if need be. Feel free to ask questions here and now if need be.
Answer:
$125 in a year ($2,625 total)
Step-by-step explanation:
We know that a percentage is out of 100 so we set up a proportion:
5/100 = x/2500
When we crossmultiply we get 12,500 then we divide by 100, getting us 125.
X = 4/5
y = 1/3
x+y = 4/5 + 1/3
x+y = 12/15 + 5/15
x+y = 17/15