A sample of size n taken from a population with mean = µ and standard deviation = σ has sample mean = µ and sample s.d. = σ/√n.
If the final exam scores are normally distributed, and X is a random variable for the mean of a sample, then
Pr[X < 70] = Pr[(X - 73) / (7.8/√24) < (70 - 73) / (7.8/√24)]
… ≈ Pr[Z < -1.8842]
… ≈ 0.0298
(where Z is normally distributed with µ = 0 and σ = 1).
Answer:
999
Step-by-step explanation:
I’m pretty sure that I’m pretty sure that question 2 is 1 minute and 40 seconds. And for number 3 I got B. 0.25 because if you look at where the line makes a direct cross between pounds and dollars that first one is 8 pounds for 2 dollars. If you divide 8 by 2 you will get 0.25. Hope this helped :)