Answer: .075 7.5% Zero point zero Seven five
Step-by-step explanation:
Answer:$25.80
Step-by-step explanation:
6.45/5 = 1.29
1.29 x 20 =25.80
Answer:
a: 28 < µ < 34
Step-by-step explanation:
We need the mean, var, and standard deviation for the data set. See first attached photo for calculations for these...
We get a mean of 222/7 = 31.7143
and a sample standard deviation of: 4.3079
We can now construct our confidence interval. See the second attached photo for the construction steps.
They want a 90% confidence interval. Our sample size is 7, so since n < 30, we will use a t-score. Look up the value under the 10% area in 2 tails column, and degree of freedom is 6 (degree of freedom is always 1 less than sample size for confidence intervals when n < 30)
The t-value is: 1.943
We rounded down to the nearest person in the interval because we don't want to over estimate. It said 28.55, so more than 28 but not quite 29, so if we use 29 as the lower limit, we could over estimate. It's better to use 28 and underestimate a little when considering customer flow.
Since sample size is > 40, we use the z-score
in calculating for the confidence interval.
The formula is given as:
Confidence Interval = X ± z * σ / sqrt (n)
Where,
X = mean = $50,340
z = z-score which is taken from standard distribution
tables at 90% confidence interval = 1.645
σ
= standard deviation = $10,780
n = sample size = 45
Substituting to the equation:
Confidence Interval = 50,340 ± 1.645 * 10,780 / sqrt (45)
Confidence Interval = 50,340 ± 1,607
Confidence Interval = $48,733 to $51,947
<span>Therefore the salary range of the personnel is $48,733 to $51,947.</span>