Consider the accompanying data on flexural strength (MPa) for concrete beams of a certain type. A B C D E F G
1 6.8 7.2 3.5 7 7.8 8.1 10.7
2 5.1 11.8 6.3 9.7 9.7 7.7 6.5
3 7.4 7.3 9 3.2 3.7 11.6 7.7
4 7.2 6.3 7.9 6.3 11.3 7
(a) Calculate a point estimate of the mean value of strength for the conceptual population of all beams manufactured in this fashion. (Round your answer to three decimal places.)
(b) Calculate a point estimate of the strength value that separates the weakest 50% of all such beams from the strongest 50%.
(c) Calculate a point estimate of the population standard deviation σ. (Round your answer to three decimal places.)
(d) Calculate a point estimate of the proportion of all such beams whose flexural strength exceeds 10 MPa. (Round your answer to three decimal places.)
(e) Calculate a point estimate of the population coefficient of variation σ/μ. (Round your answer to four decimal places.)

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!

(3x-8) or (3x+8)

step-by-step explanation:

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;