We need to find out how many adults must the brand manager survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage.
From the given data we know that our confidence level is 90%. From Standard Normal Table we know that the critical level at 90% confidence level is 1.645. In other words,
.
We also know that E=5% or E=0.05
Also, since,
is not given, we will assume that
=0.5. This is because, the formula that we use will have
in the expression and that will be maximum only when
=0.5. (For any other value of
, we will get a value less than 0.25. For example if,
is 0.4, then
and thus,
.).
We will now use the formula

We will now substitute all the data that we have and we will get



which can approximated to n=271.
So, the brand manager needs a sample size of 271
Answer:
red 420 times
Step-by-step explanation:
The results show red (18) out of ( 18+10+7+19+6)
18 / 60
18/60 * 1400 = 420 times
Answer:
B
Step-by-step explanation:
- A 95% confidence level interval will have 0.52 (lower interval) & 0.68 (upper interval) which means that that if 90 individuals root for North HS then p value is 0.6 which will fall in the 95% confidence interval range.
- For the option B the p value will also be same as in case A hence B is true as an alternative hypothesis.
- We can calculate P value
Confidence Interval = p ± z
Answer:
Answer is 49
Step-by-step explanation:
Add all the ratios up you get 21 so then you divide 147 by 21 thus giving you 1 ratio = 7 respectively, and we know the ratio of the red is 7 because it's stated red, blue, and green -> 7,6,8. So then 7 * 7 = 49. And to confirm you can do (7*7)+(6*7)+(8*7) which should equal 147
Answer:
D
Step-by-step explanation:
When multiplying numbers with the same base but different exponents, add the exponents together.