Answer:
Step-by-step explanation:
Answer:
x=-2
Step-by-step explanation:
5x -10x- 30= 10x
-5x -30 = 10x
-30=15x
x=-2
Answer:
P(Y ≥ 15) = 0.763
Step-by-step explanation:
Given that:
Mean =135
standard deviation = 12
sample size n = 50
sample mean = 140
Suppose X is the random variable that follows a normal distribution which represents the weekly supermarket expenses
Then,
The probability that X is greater than 140 is :
P(X>140) = 1 - P(X ≤ 140)
From z tables,
Similarly, let consider Y to be the variable that follows a binomial distribution of the no of household whose expense is greater than $140
Then;
∴
P(Y ≥ 15) = 1- P(Y< 15)
P(Y ≥ 15) = 1 - ( P(Y=0) + P(Y=1) + P(Y=2) + ... + P(Y=14) )
P(Y ≥ 15) = 0.763
Answer:
H0: p = 0.078
Ha: p ≠ 0.078
Step-by-step explanation:
The researchers say that the rate is about 7.8%, or 0.078 as a decimal. That makes that the null hypothesis because using "is" in math is the same as saying "equals" and the null hypothesis always has the statement of equality in it. The reason there is a not equals to sign in the alternate is for this reason as well. The researchers say it is about that amount, not more or less than that amount. So it makes this a 2 tailed test. If the amount is significantly higher or lower, then we might have to reject the null hypothesis depending on the outcome of the test.
It has three lines of symmetry.