Answer:
130
Step-by-step explanation:
4*5+10(11)
20+110
130
Enjoy!
Answer:(1) The correct option is b. (2) The correct option is c.
Explanation:
(1)
It is given that the △ABD≅△FEC.
So by (CPCTC) corresponding parts of congruent triangles are congruent.
It is given that the angle DAB is 63 degree.
Therefore, the correct option is b.
(2)
It is given that the △ABD≅△FEC.
So by (CPCTC) corresponding parts of congruent triangles are congruent.
Therefore, the correct option is c.
Answer:
Step-by-step explanation:
We want to determine a 90% confidence interval for the mean amount of time that teens spend online each week.
Number of sample, n = 41
Mean, u = 43.1 hours
Standard deviation, s = 5.91 hours
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
43.1 ± 1.645 × 5.91/√41
= 43.1 ± 1.645 × 0.923
= 43.1 ± 1.52
The lower end of the confidence interval is 43.1 - 1.52 =41.58
The upper end of the confidence interval is 43.1 + 1.52 =44.62
Therefore, with 90% confidence interval, the mean amount of time that teens spend online each week is between 41.58 and 44.62