Answer:
The margin of error for a 90% confidence interval is 16.4
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 25
Standard deviation = 50
Margin of error =
Putting the values, we get,
Thus, the margin of error for a 90% confidence interval is 16.4
68 because I found out on internet
Answer: 100
5
Step-by-step explanation:
a) The mean of a normal distribution is also the median. Half the population will have values above the mean. Half of 200 is 100, so ...
... 100 students will have grades above 70%.
b) 84% is 14% above the mean. Each 7% is 1 standard deviation, so 14% is 2 standard deviations above the mean. The empirical rule tells you 95% of the population is within 2 standard deviations of the mean, so about 5% of students (10 students) got grades higher than 84% or lower than 56%. The normal distribution is symmetrical, so we expect about 5 students in each range.
... about 5 students will have grades above 84%.
X= 100°
180° - 57° = 123
x + 23°= 123°
x = 100°
