15 I think i'm sorry if i'm wrong
Answer:
Just did it, had a good guess.
Step-by-step explanation:
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%.
$2, because if you do 8*25 you get 200 and if you divide that by 100 you get a total of 2 making the tax on the purchase $2.
Answer:
Standard error = 0.4
Step-by-step explanation:
Step 1
We find the Standard Deviation
The formula = √(x - mean)/n - 1
n = 15
Mean = 1.93 hours
= √(0- 1.93)² + (0-1.93)² +(0- 1.93)²+( 0- 1.93)²+ (1- 1.93)² + (1- 1.93)² +(1 - 1.93)² +(2 - 1.93)² + (2 - 1.93)² + (2 - 1.93)² + (2 - 1.93)² + ( 2 - 1.93)² +(4 - 1.93)² +(4 - 1.93)² + (5 - 1.93)²/15 - 1
= √(3.737777776 + 3.737777776 + 3.737777776 + 0.871111111 +0.871111111 + 0.871111111 + 0.004444444445+ 0.004444444445 + 0.004444444445 + 0.004444444445 + 0.004444444445 + 1.137777778 + 4.271111112 + 4.271111112 + 9.404444446)/15 - 1
= √2.352380952
= 1.533747356
Step 2
We find the standard error
The formula = Standard Deviation/√n
Standard deviation = 1.533747356
n = 15
= 1.533747356/√15
= 1.533747356 /3.87298334621
= 0.39601186447
Approximately = 0.4
Therefore, the standard error is 0.4
