Answer:
a) 6.68th percentile
b) 617.5 points
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

a) A student who scored 400 on the Math SAT was at the ______ th percentile of the score distribution.



has a pvalue of 0.0668
So this student is in the 6.68th percentile.
b) To be at the 75th percentile of the distribution, a student needed a score of about ______ points on the Math SAT.
He needs a score of X when Z has a pvalue of 0.75. So X when Z = 0.675.




D. 5x = 45 because you are trying to find x, the number of tickets that must be sold to earn $45.
Number 3 / last one is -49 hoped I helped you
Answer:57 pieces
Step-by-step explanation:
If the pepperoni is 26 1/2 inches long and he is cutting then 1/2 in slices. You are going to get 2 slices per inch. So multiply 26 x 2 which is 56 then add 1 for the half inch which gives you 57 slices
Answer:

And using the probability mass function we got:





And adding the values we got:

The best answer would be:
D. 0.377
Step-by-step explanation:
Let X the random variable of interest, on this case we now that:
The probability mass function for the Binomial distribution is given as:
Where (nCx) means combinatory and it's given by this formula:
For this case in order to pass he needs to answer at leat 6 questions and we can rewrite this:

And using the probability mass function we got:





And adding the values we got:

The best answer would be:
D. 0.377