Answer: (29.4, 32.6)
Step-by-step explanation:
From the question, we know that
Sample size (n) = 27
Sample mean (x) = $31
Sample standard deviation (s) = $3
We are to construct a 99% confidence interval interval for average amount spent on gift.
The formulae for constructing a 99% confidence interval for population mean is given as
u = x + tα/2 × s/√n...... For upper limit
u = x - tα/2 × s/√n...... For lower limit
tα/2 is the critical value for a 2 tailed test. This value of gotten from a t distribution table by checking the degree of freedom ( 27 - 1 = 26) against the level of significance ( 100% - 99% = 1%).
Hence tα/2 = 2.779
Let us substitute our parameters and solve
For lower limit
u = 31 - 2.779 × 3/√27
u = 31 - 2.779 ( 0.5773)
u = 31 - 1.6045
u = 29.4
For upper limit
u = 31 + 2.779 × 3/√27
u = 31 + 2.779 ( 0.5773)
u = 31 + 1.6045
u = 32.6
Hence the 99% confidence interval for population mean is given as 29.4, 32.6
Answer: X= -7
Step-by-step explanation: A negative time a negative is a positive so -12x-7 is equal to 84. 84 plus 16 is equal too 100.
You have 70% chance of picking the black marble up
Answer:
406
Step-by-step explanation:
let the 5 consecutive positive integers be
n , n + 1 , n + 2 , n + 3 , n + 4 , then
n + n + 1 + n + 2 + n + 3 + n + 4 = 2020
5n + 10 = 2020 ( subtract 10 from both sides )
5n = 2010 ( divide both sides by 5 )
n = 402
then
largest integer = n + 4 = 402 + 4 = 406
Answer:
the first one
Step-by-step explanation:
