Answer:
x = 7 and x = -1
Step-by-step explanation:
<u>Step 1: Factor</u>
x^2 - 6x - 7 = 0
(x - 7)(x + 1) = 0
<u>Step 2: Solve for x</u>
(x - 7)(x + 1) = 0
x - 7 = 0 and x + 1 = 0
x - 7 + 7 = 0 + 7 and x + 1 - 1 = 0 - 1
x = 7 and x = -1
Answer: x = 7 and x = -1
Answer:
63
Step-by-step explanation:
Answer:
Null hypothesis: the variance in hours of usage for talking is not greater than the the variance in hours of usage for internet.
: 
Alternative hypothesis: the variance in hours of usage for talking is greater than the the variance in hours of usage for internet.



Step-by-step explanation:
Let
and
be the two variables that represents the battery life in hours for talking usage and battery life in hours for internet usage respectively.
The hypothesis can be formulated as:
Null hypothesis: the variance in hours of usage for talking is not greater than the the variance in hours of usage for internet.
: 
Alternative hypothesis: the variance in hours of usage for talking is greater than the the variance in hours of usage for internet.

The standard deviation for the battery usage for talking is :

The standard deviation Is:




The standard deviation for the battery life usage for the internet is :




Thus; the standard deviation is:




Answer:
0.139
Step-by-step explanation:
We are given that
Total number of cards=52
n=18
We have to find the probability of drawing at least 7 spades
Total number of spaded in deck of 52 cards=13
Probability of getting spade=
Probability,
Probability of getting no spade=
By binomial theorem of probability

P(x
The probability of drawing at least 7 spades=
The probability of drawing at least 7 spades=0.139