Answer:
Step-by-step explanation:
so 2/5 of 100 contain chocolate...
2/5 * 100 = 200/5 = 40 <== contain chocolate
Position vector R = < 4,0,1>
(given point)
normal vector n = < 3,-1,9>
equation:
n(r-R) = 0
3(x-4) - y + 9(z-1) = 0
Let x be the unknown number of years.
Let C be Chris' age and J be Jenny's age.
Then J+x = 2(C+x)-7
... describes this situation.
4+x = 2(2+x) - 7
4+x = 4 + 2x - 7
x = 2x -7 becomes 7=x
In 7 years, Jenny will be 7 years younger than twice Chris' age.
Check: Is this true? 4+7 = 2(2+7)-7
11 = 18-7, or 11=11 TRUE
Answer:
Step-by-step explanation:
We want to determine a 95% confidence interval for the mean salary of all graduates from the English department.
Number of sample, n = 400
Mean, u = $25,000
Standard deviation, s = $2,500
For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean ± z × standard deviation/√n
It becomes
25000 ± 1.96 × 2500/√400
= 25000 ± 1.96 × 125
= 25000 ± 245
The lower end of the confidence interval is 25000 - 245 =24755
The upper end of the confidence interval is 25000 + 245 = 25245
Therefore, with 95% confidence interval, the mean salary of all graduates from the English department is between $24755 and $25245
