Answer: The 95% confidence interval is approximately (55.57, 58.43)
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Explanation:
At 95% confidence, the z critical value is about z = 1.960 which you find using a table or a calculator.
The sample size is n = 17
The sample mean is xbar = 57
The population standard deviation is sigma = 3
The lower bound of the confidence interval is
L = xbar - z*sigma/sqrt(n)
L = 57 - 1.960*3/sqrt(17)
L = 55.5738905247863
L = 55.57
The upper bound is
U = xbar + z*sigma/sqrt(n)
U = 57 + 1.960*3/sqrt(17)
U = 58.4261094752137
U = 58.43
Therefore the confidence interval (L, U) turns into (55.57, 58.43) which is approximate.
Answer:
16
Step-by-step explanation:
Solve 5 to the power of x minus 3 to the power of x when x=2.
So, you do 5 to the power of 2 minus 3 to the power of 2, which is 25-9=16
Answer:
Milan puts 1/4 of her lawn-mowing money in savings and uses 1/2 of the remaining money to pay back her sister. If she has $15 left
Step-by-step explanation:
Answer:
a= 18 girls in the class, b= 20 boys and 15 girls, 12 oranges better price.
Step-by-step explanation:
for question a, there are 18 girls in the class, this is how i worked it out:
the ratio of boys to girls is 4:3.
there are 24 boys.
24 is 6 times more than 4.
if boys are 6 times more than the original ratio, we also have to times the amount of girls by 6.
6x3= 18.
for question b i got 20 boys and 15 girls, this is how i did it.
there are 35 students in total.
4:3= boys to girls.
4+3=7
7 goes into 35 five times.
ratio of boys to girls is 4:3 so 5x4 for boys = 20 and 3x5 for girls = 15.
answer= 20 boys and 15 girls.
12 oranges is a better deal, this is how i worked it out.
it is 60 for 12 oranges.
it is 48 for 8 oranges.
12x5= 60 , 8x6=48.
you only have to times 12 by 5 to get it to the price but you have to times 8 by 6 to get it to the price, proving that 12 oranges for 60 is a better deal.
