Answer:
The mistake was minus sign before the 15 and putting 15x² instead of 15x³.
The correct answer is:
Answer:
78%, no he didn't score high enough
Step-by-step explanation:
Answer:
5
Step-by-step explanation:
8*5=40 and then 20 short answer that are 3 each. that makes up the rest of the 60 points
Answer:
the probability that the sample variance exceeds 3.10 is 0.02020 ( 2,02%)
Step-by-step explanation:
since the variance S² of the batch follows a normal distribution , then for a sample n of 20 distributions , then the random variable Z:
Z= S²*(n-1)/σ²
follows a χ² ( chi-squared) distribution with (n-1) degrees of freedom
since
S² > 3.10 , σ²= 1.75 , n= 20
thus
Z > 33.65
then from χ² distribution tables:
P(Z > 33.65) = 0.02020
therefore the probability that the sample variance exceeds 3.10 is 0.02020 ( 2,02%)
