What are you tryin to say
Let j = cost of one jumbo popcorn, and c = cost of one chocolate chip cookie.
Then, based upon the given info, 1j + 2c = $5.
Also, 3j + 5c = $14.50
Let's solve this system of equations using addition/subtraction:
Mult. the first equation by -3, to obtain -3j - 6c = -$15
Now add this result to the 2nd equation:
-3j - 6c = -$15
3j + 5c = $14.50
----------------------
-c = -$0.50, or c = $0.50. Since 3j + 5c = $14.50, subst. $0.50 for c
lets us find j:
3j + 5($0.50) = $14.50, so 3j = $12.00. Thus, j = $4.00.
Jumbo popcorn is $4/bag, and choc. chip cookies $0.50 each.
Answer:
A) sample mean = $1.36 million
B) standard deviation = $0.9189 million
C) confidence interval = ($1.93 million , $0.79 million)
*since the sample size is very small, the confidence interval is not valid.
Step-by-step explanation:
samples:
- $2.7 million
- $2.4 million
- $2.2 million
- $2 million
- $1.5 million
- $1.5 million
- $0.5 million
- $0.5 million
- $0.2 million
- $0.1 million
sample mean = $1.36 million
the standard deviation:
- $2.7 million - $1.36 million = 1.34² = 1.7956
- $2.4 million - $1.36 million = 1.04² = 1.0816
- $2.2 million - $1.36 million = 0.84² = 0.7056
- $2 million - $1.36 million = 0.64² = 0.4096
- $1.5 million - $1.36 million = 0.14² = 0.0196
- $1.5 million - $1.36 million = 0.14² = 0.0196
- $0.5 million - $1.36 million = -0.86² = 0.7396
- $0.5 million - $1.36 million = -0.86² = 0.7396
- $0.2 million - $1.36 million = -1.16² = 1.3456
- $0.1 million - $1.36 million = -1.26² = 1.5876
- total $8.444 million / 10 = $0.8444 million
standard deviation = √0.8444 = 0.9189
95% confidence interval = mean +/- 1.96 standard deviations/√n:
$1.36 million + [(1.96 x $0.9189 million)/√10] = $1.36 million + $0.57 million = $1.93 million
$1.36 million - $0.57 million = $0.79 million
<span>(<span><span>−x</span>+4</span>)</span><span>(<span>x−8</span><span>) is the simplest form.</span></span>
