Explain what is Beta Co-efficient and using examples explain how betas are used in risk analysis?

Explain what is Beta Co-efficient and using examples explain how betas are used in risk analysis?

Sarah Palin has $35,000 invested in a GHL stock that has a beta of 0.8 and $40,000 invested in a Scotia Bank stock with a beta of 1.4. If these are the only investments in her portfolio, what is her portfolio's beta? Show workings.