Answer:
52
Step-by-step explanation:
Given that :
Mean (m) = 78
Standard deviation (s) = 13
Score that is 2 standard deviations below the mean
Using the relation :
Zscore = (x - m) / s
2 standard deviations below the mean means a Zscore of - 2
Hence,
-2 = (x - 78) / 13
Cross multiply
-2 * 13 = x - 78
-26 = x - 78
x = - 26 + 78
x = 52
Score which is 2 standard deviations below the mean is 52
Given:
Population proportion,

= 57% = 0.57
Population standard deviation, σ = 3.5% = 0.035
Sample size, n = 40
Confidence level = 95%
The standard error is

The confidence interval is

where

= sample proportion
z* = 1.96 at the 95% confidence lvvel
The sample proportion lies in the interval
(0.57-1.96*0.0783, 0.57+1.96*0.0783) = (0.4165, 0.7235)
Answer: Between 0.417 and 72.4), or between (41% and 72%)
Answer:
10 points
Step-by-step explanation:
per 2 days you lose 5 points. To get to 4 days you multiply 2 by 2 and get 4 and 5 by 2 and get 10. So per 4 days he loses 10 points.