Answer:
40
Step-by-step explanation:
6% of number = 6/100 × x = 6x/100 = 3x/50
Sum of the number and 6% of itself = 42.4
x + (3x/50) = 42.4
(50x+3x)/50 = 42.4
53x = 42.4 × 50
53x = 2120
x = 2120/53
x = 40
Answer:
C
Step-by-step explanation:
Using the z-distribution, it is found that the 95% confidence interval for the proportion of sales that occured in December is (0.1648, 0.2948).
<h3>What is a confidence interval of proportions?</h3>
A confidence interval of proportions is given by:

In which:
is the sample proportion.
In this problem, we have a 95% confidence level, hence
, z is the value of Z that has a p-value of
, so the critical value is z = 1.96.
The sample size and the estimate are given by:

Hence:


The 95% confidence interval for the proportion of sales that occured in December is (0.1648, 0.2948).
More can be learned about the z-distribution at brainly.com/question/25890103