D + t = total earnings
$3h + t = total earnings
$3h + $22 = total earnings
Fill in h as however many hours she is working.
Example: She worked for 8 hrs and got $22 in tips.
$3(8) + $22 = ?
$24 +$22 = $46
X + 12 = 20
x + 12 -12 = 20 -12
x = 8
Answer:
21.759
Step-by-step explanation:
Given that :
Mean (m) = 25
Standard deviation (s) = 12.5
Sample size (n) = 40
α = 90%
The confidence interval is obtained using the relation:
Mean ± Zcritical * s/sqrt(n)
Zcritical at 90% confidence interval = 1.64
25 ± 1.64 * (12.5/sqrt(40))
Lower boundary : 25 - 1.64(1.9764235) = 21.75866546
Upper boundary : 25 + 1.64(1.9764235) = 28.24133454
(21.759, 28.241)
Hence, lower bound of confidence interval is : 21.759
Let X be the iq score of adults. X is normally distributed with mean of 100 and standard deviation of 20.
If all iq scores are converted to z -scores then we will get z scores. And the z score is standard normal variable with mean=0 and standard deviation =1
Hence the mean and standard deviation of of all z scores will be 0 and 1 respectively.
