Complete question :
The average daily volume of a computer stock in 2011 was p = 35.1 million shares, according to a reliable source. A stock analyst believes that the stock volume in 2014 is different from the 2011 level. Based on a random sample of 40 trading days in 2014, he finds the sample mean to be 30.9 million shares, with a standard deviation of s = 11.8 million shares. Test the hypotheses by constructing a 95% confidence interval. Complete parts (a) through (c) below. State the hypotheses for the test. Construct a 95% confidence interval about the sample mean of stocks traded in 2014.
Answer:
H0 : μ = 35.1 ;
H1 : μ < 35.1 ;
(26.488 ; 35.312)
Step-by-step explanation:
The hypothesis :
H0 : μ = 35.1
H1 : μ < 35.1
The confidence interval :
Xbar ± Margin of error
Xbar = 30.9
Margin of Error = Zcritical * s/sqrt(n)
Zcritical at 95% = 1.96
Margin of Error = 1.96 * (11.8/sqrt(40))
Margin of Error = 4.412
Lower boundary :
30.9 - 4.412 = 26.488
Upper boundary :
30.9 + 4.412 = 35.312
Confidence interval = (26.488 ; 35.312)
Since the population mean value exists within the interval, the we fail to reject the Null.
Answer:
38
Step-by-step explanation:
We can express the 8th term as x and the 12th term as y.
This would mean that 8x=12y
Because the common difference between terms is -2 and term 8 and term 12 are 4 terms apart, this means that the 12th term is 8 less than the 8th term, so x-8=y
Now we can use this to substitute y with x in the first equation. This would give us:
8x=12(x-8)
Which we can expand and solve:
8x=12x-96
-4x=-96
Therefore x=24
This means the 8th term is 24 and the 12th term is 16 (24-8).
To test if this is correct we can do:
8x24=12x16
Which indeed are equal, both sides multiply to 192.
Now that we have our 8th term, we can find the 1st term, which is 7 terms away, therefore we just add 14 to the 8th term 24. (7x2=14)
24+14=38.
The first term is 38.
Hope this helped!
There are 70 days in 10 weeks
10*7=70
Answer:
The kind of ice cream the least number of students prefer is Strawberry ice cream.
Step-by-step explanation:
We convert all given values to decimal
Hiroshi found that:
a) For vanilla ice cream
3/5 of his class prefers vanilla ice cream
3/5 to decimal = 0.6
b) For Chocolate ice cream
26% prefers chocolate ice cream
26% to decimal = 0.26
c) For strawberry ice cream
0.14 prefers strawberry ice cream
0.14 = 0.14
Arranging the numbers in order from least to greatest, we have :
0.14, 0.26 , 0.6
The kind of ice cream the least number of students prefer is Strawberry ice cream.